CA3069719A1 - Slide assembly - Google Patents

Abstract

ABSTRACT
Some embodiments described herein include a slide assembly defining a gas port to provide a firearm with gas compensation to reduce recoil, an optic mounting platform, and/or an alignment system to restrict movement of the muzzle end of the barrel within a plane perpendicular to a bore axis of the barrel and prevent rotational movement of the barrel relative to the slide.

Description

SLIDE ASSEMBLY
BACKGROUND
[0001] Typical firearms propel a bullet or other type of projectile through the expansion of gas within a firearm barrel. The majority of the gas may be expelled out of the front of the firearm barrel together with the bullet. However, some firearms may exploit a portion of the gas to reduce recoil.

[0002]
An accessory called a compensator can be used to retrofit a firearm with recoil reduction. These accessories are attached to the muzzle end of the barrel.
However, this increases the total length of the firearm.
BRIEF DESCRIPTION OF THE DRAWINGS

[0003] FIG. IA illustrates a slide assembly including a bottom view of a slide and a side view of a barrel.

[0004] FIG. 1B illustrates a partial top view of a slide with an MOS (modular optic system) cover plate removed:

[0005] FIG. 1C illustrates a bottom view of an MOS adapter plate.

[0006] FIG. 1D illustrates a slide assembly in which the MOS adapter plate of FIG. 1C is installed on the slide of FIG. 1B.

[0007] FIG. 1E illustrates installation of a sealing plate on the slide assembly of FIG. 1D.

[0008] FIG. 1F illustrates a bottom view of an RMR (rugged miniature reflex) optic.

[0009] FIG. 1G illustrates the RMR optic of FIG. 1F and the sealing plate of FIG. 1E installed on the slide assembly of FIG. 1D.

[0010] FIG. 2A illustrates a bottom view of a slide for a slide assembly to provide a firearm with gas compensation to reduce recoil.

[0011] FIG. 2B illustrates a front view of the slide of FIG. 2A.

[0012] FIG. 3 illustrates a front view of a barrel operable with the slide of FIGS. 2A-B.

[0013] FIG. 4A illustrates a partial side view of firearm having slide assembly including the slide illustrated in FIGS. 2A-B and the barrel illustrated in FIG. 3.

[0014] FIG. 413 illustrates a partial side view of firearm of FIG. 4A in which the slide is retracted.

[0015] FIG. 5A illustrates a perspective view of a muzzle end of a slide assembly having a gas port formed from an egress in a barrel, a front surface of an arch on the underside of the slide, an opening in the slide, and an interior of a front end of the slide.

[0016] FIG. 5B illustrates a top view of the slide assembly of FIG. 5A.
f00171 FIG. 5C illustrates a cross-sectional view of the slide of the slide assembly of FIG. 5A
taken across a width of the slide assembly.
[0018] FIG. 5D illustrates a bottom view of the slide assembly.
[0019] FIG. 5E illustrates a partial side view of the barrel of the slide assembly of FIG. 5A.
[0020] FIG. 6A illustrates a cross-sectional view of a muzzle end of the slide assembly of FIG.
5A taken across a length of the slide assembly.
[0021] FIG. 6B illustrates a cross-sectional view taken along line AL of FIG.
5A.
[0022] FIG. 6C illustrates a cross-sectional view taken along line AC of FIG.
5A.
[0023] FIG. 6D illustrates a cross-sectional view taken along line AD of FIG.
5A.
[0024] FIG. 6E illustrates a cross-sectional view taken along line AK of FIG.
5A.

[0025] FIG. 7A illustrates a side view of a barrel in which rifling may be preserved between the muzzle end of the barrel and a location coinciding with a front-most edge of the egress.
[0026] FIG. 7B illustrates a cross-sectional view taken across a width of the barrel of FIG. 7A.
[0027] FIG. 7C illustrates a cross-sectional view taken along line BA of FIG.
7B.
[0028] FIG. 7D illustrates a detailed view of the chamfer on a front-most bore edge of the egress.
[0029] FIG. 8A illustrates a side view of another barrel in which rifling may be preserved between the muzzle end of the barrel and a location coinciding with a front-most edge of the egress.
[0030] FIG. 8B illustrates a cross-sectional view taken across a width of the barrel of FIG. 8A.
[0031] FIG. 8C illustrates a cross-sectional view taken along line BC of FIG.
8B.
[0032] FIG. 9A illustrates a side view of yet another barrel in which rifling may be preserved between the muzzle end of the barrel and a location coinciding with a front-most edge of the egress.
[0033] FIG. 9B illustrates a cross-sectional view taken across a width of the barrel of FIG. 9A.
[0034] FIG. 9C illustrates a cross-sectional view taken along line AY of FIG.
9B.
100351 FIG. 10A illustrates a cross-sectional view taken across a width of a slide assembly with an alignment system to restrict movement of the muzzle end of the barrel within a plane perpendicular to a bore axis of the barrel and prevent rotational movement of the barrel relative to the slide.
[0036] FIG. 10B illustrates a cross-sectional view taken across a width of the slide assembly of FIG. 10A.
[0037] FIG. 10C illustrates a cross-sectional view taken along line AW of FIG.
10B.
[0038] FIG. 10D illustrates a cross-sectional view taken along line AV of FIG.
10B.
[0039] FIG. 10E illustrates a cross-sectional view taken along line AU of FIG.
10B.

[0040] FIG. 11A illustrates a partial top view of a slide assembly including an optic mounting platform integrally formed on the top of the slide and a grip for charging the slide integrally formed from sides below the optic mounting platform.
[0041] FIG. 11B illustrates a partial side view of the slide assembly of FIG.
11A.
[0042] FIG. 11C illustrates the slide of FIGS. 11A-B being charged using the grip that is integrally formed from the sides below the optic mounting platform.
[0043] FIG. 11D illustrates a back view of a slide assembly in an embodiment in which the exterior sides of the slide are inward sloping from an upper location below the optic mounting platform to a lower location below the upper location.
[0044] FIG. 11E illustrates a back view of a slide assembly in another embodiment including an optical mounting platform overhanging completely vertical exterior surfaces of sides of the slide.
[0045] FIG. 12 illustrates a partial side view of a slide assembly in which the RMR optic illustrated in FIG. 1F is mounted directly on the slide illustrated in FIGS.
11A-C.
[0046] FIG. 13 illustrates a partial side view of an optic guard with an integrated rear sight.
[0047] FIG. 14A illustrates a side view of an optic guard usable with the slide and the optic shown in FIG. IF.
[0048] FIG. 14B illustrates a partial side view of a firearm including the optic guard of FIG.14A
installed thereon.
[0049] FIG. 14C illustrates a partial side view of a firearm including the optic guard of FIG.14A
with the RMR optic illustrated in FIG. 1F installed thereon.
[0050] FIG. 14D illustrates charging a slide using a grip location provided on an optic guard.
[0051] FIG. 15 illustrates an optic guard including a frame welded to a bracket.

[0052] FIGS. 16A-B illustrate partial side views of another embodiment of a slide assembly to provide a firearm with gas compensation to reduce recoil in which the barrel includes a sight tracker.
[0053] FIGS. 16C-D illustrate perspective and side views (respectively) of the barrel of the slide assembly of FIGS. 16A-B.
DETAILED DESCRIPTION
Slide assembly to provide gas compensation to reduce recoil [0054] Services have been offered to bore openings in a slide assembly to guide gas propelled from a chamber of a firearm in a direction to provide recoil reduction. The service provider obtains a slide assembly from the customer, removes material from various components of the slide assembly, and then returns the slide assembly to the customer.
[0055] In some services, the service provider removes material from a top half of the barrel to form a gas port. The service provider may also remove material from the top and/or sides of the slide around the gas port in the barrel in an attempt to vent some of the gas exiting the gas port out top and/or sides the slide. However, if these slide vents are not effective at venting the gas exiting the gas port, then the unvented gas may distribute carbon particles throughout the firearm, which may eventually degrade operation of the firearm.
[0056] Also, remove the material from the gas port in the barrel may leave burs that may contact a bullet passing by the gas port (on its way to the muzzle) ¨ changing its trajectory. These burs may also strip material from the passing bullet. This stripped material, like the carbon particles, may be distributed through the firearm, which may eventually degrade operation of the firearm (also the stripped material is a safety concern for the shooter and/or bystanders).
[0057] FIG. 1A illustrates a slide assembly including a bottom view of a slide 100 and a side view of a barrel 105. In this example, the slide 100 and barrel 105 are Glock-compatible. A Glock-compatible firearm component is compatible with the Glock design (but may be produced by a third party).

[0058] The barrel 105 includes a breech 3, a muzzle 2, and a length including a cylindrical bore length segment 4 (which includes the bore of the barrel 105) and a non-cylindrical barrel hood segment 5 (which includes the chamber of the barrel 105).
[0059] When the barrel 105 is locked into the slide 100, a tip of the muzzle end of the barrel 105 protrudes from the front of the slide 100. There are gaps between the rest of the bore length segment and the interior of the top and the sides of the slide 100. In particular, the width (wl ) of the interior of the slide 100 corresponds to the width of the barrel hood, which accommodates rearward movement of the slide 100 relative to the barrel 105 following firing of the firearm. A
wear marking 19 can be seen on the underside of the top of the slide 100 where the top of the barrel hood 18 (e.g., the side opposite the lugs 6) slides against the underside of the top of the slide 100 during this movement (the length of this wear marking 19 corresponds to the length of stroke of the firearm). In this slide assembly, these gaps are continuous from the opening 13 (which receives the top 18 of the barrel hood) past the sight mount 5 to the front interior wall 12 of the slide.
[0060] FIG. 2A illustrates a bottom view of a slide 200 for a slide assembly to provide a firearm with gas compensation to reduce recoil. FIG. 2B illustrates a front view of the slide 200.
[0061] The slide 200 may have the same compatibility as the slide 100 of FIG.
1. For instance, the slide 200 may be a retrofit for a firearm manufactured with the slide 100 of FIG. 1, in some examples (the slide 200 of course may also be an original part of a firearm, in other examples).
[0062] The interior of the top and sides of the slide 200 define an arch 21. A
width (w2) of an interior of the arch 21 may be less than the width (w 1 ). The same reference number w 1 is used to indicate that the width behind the arch 21 may be the same as the width between the interior sides of the slide 100 of FIG. 1A. The width (w2) may correspond to a width of the bore length segment 4 (FIG. 1A).
[0063] Behind the arch 21 is a barrel hood channel 20 with the width (w 1 ) and a depth (d 1 ) corresponding to a height of the barrel hood 5 (FIG. 1A). The barrel hood channel 20 may receive the barrel hood through a range of motion of the slide 200 relative to the barrel responsive to a firing of the firearm. When the barrel is locked into the slide 200, a gap between the bore length segment of the barrel and the interior top and sides of the slide 200 in the barrel hood channel 20 may be the same as the gap with the bore length segment 4 and interior of the sides of the slide 100 (FIG. 1). In contrast, in a slide assembly using the slide 200, the gap between the bore length segment and the protrusions that define the interior sides and underside of the arch 21 may be less.
In some embodiments, an underside of the arch 21 may be arranged to slidingly engage the upper region of the bore length segment in part of the range of motion (although this is not required). In some embodiments, the width (w2) may be at least the width of the bore length segment.
[0064] FIG. 3 illustrates a front view of a barrel 300 operable with the slide 200 of FIGS. 2A-B. An upper section of the barrel 300 (proximate to the muzzle 32) defines an egress 39 for gas propelled from the chamber of the firearm. In this example, a rib 38 is located between the openings. The egress 39 may be formed by removing material from a barrel similar to the barrel 105 (FIG. 1A).
[0065] Referring again to FIGS. 2A-B, the slide 200 may define an opening 23 in front of the arch 21 to expose the egress 39 (FIG. 3). In this embodiment, the opening 23 is a single contiguous opening; however, this is not required. Also, in this embodiment, the opening 23 is defined by protrusions on both the top and sides of the slide 200; however, this is not required. In other embodiments, the opening 23 may be defined by protrusions on the top and/or sides of the slide 200.
[0066] In this embodiment, protrusions 22 defined by the interior of the sides of the slide 200 may be located in front of the arch 21. The distance between surfaces of the protrusions 22 may be the same as the distance w2.
[0067] The slide 200 may include a sight mount opening 25 behind the arch 21.
In this embodiment, the slide 200 also includes a window 27 located behind the arch 21 (the window 27 may facilitate cooling of the barrel 300; however, other embodiments may omit the window 27).
[0068] Referring again to FIG. 3, removing material from the egress 39 may be selective to form a rib 38 between separate bore openings of the egress 39. The exterior of the rib 38 is arranged to engage the underside of the arch 21 (FIG. 2A) following firing. This engagement prevents the underside of the arch 21 from catching on the egress 39. By selectively removing material from the egress 39 to leave the rib 38, the size of the egress 39 may be optimized to extend across substantially all of an upper half of a front section of the bore length segment of the barrel 300.
[0069] FIG. 4A illustrates a partial side view of firearm having slide assembly 400 including the slide 200 illustrated in FIGS. 2A-B and the barrel 300 illustrated in FIG.
3. FIG. 4B illustrates a partial side view of firearm of FIG. 4A in which the slide 200 is retracted.
[0070] This embodiment includes a gas' port 49 formed by the egress 39 of the barrel 300, a front surface 45 of the arch 21 (FIGS. 2A-B), the protrusions 22 (FIGS. 2A-B), an interior of a front of the slide 200, and the opening 23 (FIGS. 2A-B). In particular, sidewalls of the gas port 49 may include a surface of sidewalls of the egress 39, the front surface 45 of the arch 21, a surface of the protrusions 22, a surface of the interior of the front of the slide 200, and a surface of sidewalls of the opening 23. In other embodiments, a barrel gas port may be located a distance from one or more of the front surface 45 (the arch 21 may be located a distance behind the barrel gas port), a distance from surfaces of the interior of the sides of the slide (these surfaces may or may not include the protrusion 22), a distance from a surface of the interior of the front of the slide, and/or a distance from a surface of sidewalls of opening(s) in the slide.
[0071] In this embodiment, a group 48 of holes is located on the sides 42 of the slide (only one of the sides 42 is shown in this view). Each hole may include a first end on the exterior surface of the sides 42 and a second end on a sidewall of the gas port 49. The group 48 of holes may be omitted in other embodiments.
[0072] A transition edge between the top 41 and sides 42 of the slide 200 may be sloped (e.g., a beveled edge). A portion of a perimeter of the opening 23 (FIGS. 2A-B) in the slide 200 may be located on this sloped edge, as in the illustrated embodiment; however, this is not required.
[0073] FIG. 5A illustrates a perspective view of a muzzle end of a slide assembly having a gas port formed from an egress in a barrel, a front surface of an arch on the interior of the slide, an opening in the slide, and an interior of a front end of the slide. In this embodiment, the back wall 51 of the gas port is a continuous wall defined by a front surface of an arch and a back wall of the barrel egress (the arch may be similar in any respect to the arch 21 of FIGS.
2A-B).

[0074] FIG. 5B illustrates a top view of the slide assembly of FIG. 5A. The sides 52 of the gas port is a continuous wall defined by protrusions on an interior of the slide (the protrusions may be similar in any respect to protrusions 22 of FIGS. 2A-B) and extending to meet up with the bottom edge of the barrel egress of the barrel.
[0075] FIG. 5C illustrates a cross-sectional view of the slide assembly of FIG. 5A taken across a width of the slide assembly. In this view, the alignment 54 of the barrel egress to a slide opening geometry is shown.
[0076] FIG. 5D illustrates a bottom view of the slide assembly. The protrusions on the interior surface of the sides of the slide may sealingly engage 53 the barrel.
[0077] FIG. 5E illustrates the barrel of the slide assembly of FIG. 5A. This barrel may be similar in any respect to barrel 300 of FIG. 3. This barrel optionally includes scalloping, which may be visible through a window similar to window 27 (FIG. 2A).
[0078] FIG. 6A illustrates a cross-sectional view of a muzzle end of the slide assembly of FIG.
5A taken across a length of the slide assembly. FIG. 6B illustrates a cross-sectional view taken along line AL of FIG. 6A. FIG. 6C illustrates a cross-sectional view taken along line AC of FIG.
6A. A gas port 61 formed by an egress in a barrel and an opening in a slide is shown (this gas port may be similar in any respect to any gas port described herein).
[0079] FIG. 6D illustrates a cross-sectional view taken along line AD of FIG.
6A. Behind the gas port 61 (FIG. 6C), material 62 of protrusions on an interior of the top and sides of the slide extend toward the barrel. This material 62 may be material of an arch similar to arch 21 of FIG.
2A. FIG. 6E illustrates a cross-sectional view taken along line AK of FIG. 6A.
A barrel hood channel 63 is shown in this view.
[0080] FIGS. 16A-B illustrate a partial side view of another embodiment of a slide assembly 1600 to provide a firearm with gas compensation to reduce recoil in which the barrel 1630 includes a sight tracker 1699. The barrel 1630 is locked with the slide 1620 in the partial side view of FIG.
16A. The partial side view of FIG. 16B shows a state following firing once the slide 1620 has moved relative to the barrel 1630.

[0081] Referring again to FIG. 16A, the slide 1620 may be similar to slide 200 (FIG. 2A) in any respect. The barrel 1630 may be similar to barrel 300 (FIG. 3) in any respect.
The gas port 1649 may be similar to gas port 49 (FIG. 4A) in any respect. The sight tracker 1699 includes a rib section 1650 . In this embodiment of the sight tracker 1699, the sight tracker 1699 defines an additional gas port 1680 (cut through a center of the rib section 1650 and exposing an egress at an uppermost part of the barrel).
[0082] As shown in FIG. 16B, a top surface of sight tracker 1699 may protrude from the slide 1620 at least following a firing of the firearm (when the front of the barrel 1630 may rise with respect to the slide 1620). Using the sight tracker 1699, and due to the recoil reduction provided by the gas port 1649, a user may continue tracking a target more easily from one round to the next than in the same firearm without the firearm assembly 1600.
[0083] In this embodiment, an arc segment 1631 (FIG. 16A) of the barrel is located between an edge of the egress 1639 and the sight tracker 1699. FIGS. 16C-D illustrate perspective and side views (respectively) of the barrel 1630. The arc segment 1631 is shown in detail in FIG. 16C. In contrast to the sight opening 5 (FIG. 1A) which is in the slide 100, this front sight mount 1695 is part of the barrel. In this embodiment, the front sight mount 1695 is a dovetail groove, but other embodiments may utilize some other groove (or some other structure to mate with a bottom of a front sight). In other embodiments, a front sight and the barrel may be a unitary structure.
Barrel interior [0084] An egress on a barrel may be deburred to clear a path for the bullet.
Also, to prevent stripping material from the bullet, some of the rifling inside the barrel near the muzzle may be removed (which may reduce stripping of the bullet as it passes the egress).
Essentially, the muzzle end of the bore may be bored out by a tool inserted into the muzzle end of the barrel to remove rifling of the muzzle end of the bore to reduce or prevent bullet stripping.
[0085] If the rifling is removed on an interior of rib 38 (FIG. 3), the bullet trajectory may be impacted. One approach is to remove rifling from only from the muzzle end of the barrel to a location corresponding with a front-most edge of the egress 39 ¨ preserving the rifling on the interior of the rib 38 and stopping the front-most edge of the egress 39 from stripping bullets. This may eliminate bullet stripping while preserving a trajectory of the bullet.
However, other approaches are described below, and these approaches may eliminate bullet stripping without requiring removal of the rifling between the muzzle end of the barrel and the location corresponding with a front-most edge of the egress 39.
[0086] FIG. 7A illustrates a side view of a barrel 700 in which rifling may be preserved between the muzzle end 702 of the barrel and a location coinciding with a front-most edge of the egress 739. The barrel 700 may be similar in any respect to the barrel described with reference to FIG.
3, or any other barrel described herein.
[0087] FIG. 7B illustrates a cross-sectional view taken across a width of the barrel 700 of FIG.
7A. In this example, the egress 739 spans a distance from a middle of the side of the barrel to an edge of the rib 738 at the top of the barrel 700. As mentioned previously, the rifling on the inside of the rib 738 guides a trajectory of a bullet.
[0088] FIG. 7C illustrates a cross-sectional view taken along line BA of FIG.
7B. In this view, the chamfer 710 on the bore-edge of the egress 739 is visible. FIG. 7D
illustrates a detailed view of the chamfer 710 on a front-most bore-edge of the egress. This chamfer 710 may be provided on an entire front-most bore edge of the egress 739. Other edges may include chamfers, although chamfers are not required on the entirety of the other edges to prevent bullet stripping. The chamfer 710 may be formed by removing material from the egress 739, and then cutting the chamfer 710 on the front-most edge of the egress 739.
[0089] FIG. 8A illustrates a side view of another barrel in which rifling may be preserved between the muzzle end of the barrel and a location coinciding with a front-most edge of the egress.
FIG. 8B illustrates a cross-sectional view taken across a width of the barrel of FIG. 8A. FIG. 8C
illustrates a cross-sectional view taken along line BC of FIG. 8B. In this view, the circumferential groove 810 can be seen. The circumferential groove 810 may have sloped sidewalls (e.g., a V-shaped groove) in which the circumferential groove 810 is centered just behind the front-most edge of the egress 839.
[0090] FIG. 9A illustrates a side view of yet another barrel in which rifling may be preserved between the muzzle end of the barrel and a location coinciding with a front-most edge of the egress.

FIG. 9B illustrates a cross-sectional view taken across a width of the barrel of FIG. 9A. FIG. 9C
illustrates a cross-sectional view taken along line AY of FIG. 9B. In this view, the circumferential groove 910 can be seen. The circumferential groove 910 may have sloped sidewalls (e.g., sidewalls similar to circumferential groove 810 of FIG. 8C) and additionally may have a bottom width between bottoms of the sidewalls.
100911 In one example, the bottom width may be a flat bottom, although this is not required.
The circumferential groove 910 need not necessarily be centered on the front-most bore-edge of the egress 939. This may improve manufacturing tolerances as compared to the chamfer 710 or the V-shaped circumferential groove. The front-most edge of the egress may coincide with any portion of the bottom width.
Alignment system to control movement of a barrel relative to a slide 100921 FIG. 10A illustrates a cross-sectional view taken across a width of a slide assembly 1000 with an alignment system 1099 to restrict movement of the muzzle end of the barrel 1030 within a plane perpendicular to a bore axis of the barrel 1030 and prevent rotational movement of the barrel 1030 relative to the slide 1020. The bore axis is the center of a bore extending from a start of the bore to the muzzle end of the bore (in this view, the bore axis is at a center of the bore of the barrel 1030 going into the page, and the plane coincides with the page).
100931 The alignment system 1099 includes a groove or protrusion located on the bore length segment of the barrel 1030. This groove or protrusion mates with a protrusion or groove defined by an interior surface of the slide. In this embodiment, the bore length segment of the barrel 1030 is non-cylindrical, and the alignment system 1099 includes a protrusion on a top of the barrel 1030 (e.g., the pointed top of the non-cylindrical bore length segment). In this embodiment, the protrusion mates with a groove defined by an underside of a top of the slide 1020. The alignment system 1099 reduces lateral movement of the muzzle end of the barrel 1030 within the plane (e.g., prevents movement of the barrel to the left or right).
[00941 FIG. 10B illustrates a cross-sectional view taken across a width of the slide assembly of FIG. 10A. FIG. 10C illustrates a cross-sectional view taken along line AW of FIG. 10B. FIG.
10D illustrates a cross-sectional view taken along line AV of FIG. 10B. FIG.
10E illustrates a cross-sectional view taken along line AU of FIG. 10B. FIGS. 10C-E illustrate that the slide assembly 1000 provides gas compensation to reduce recoil. In particular, an arch 1021 is shown in FIG. 10E, and this arch may be similar in any respect to arch 21 (FIG. 2A).
[0095] The arch 1021 includes a triangular shaped underside, in contrast to the rounded underside of the arch 21 (which does not include the alignment system 1099).
Other examples including of slide assemblies to provide gas compensation to reduce recoil and with an alignment system may have differently shaped arches (for instance, it may be possible and practical to have a protrusion from an underside of the arch to mate with a groove formed on an upper section of a non-cylindrical barrel).
[0096] Also, some embodiments of a slide assembly that do not provide gas compensation to reduce recoil may utilize an alignment system similar to alignment system 1099. Such an embodiment may not include an arch similar to arch 21 (FIG. 2A) or arch 1021.
However, an underside of the slide in such an embodiment may include the protrusion or groove on an underside of a front of the slide (e.g., a non-cylindrical opening in the front of the slide to receive a non-cylindrical bore length segment of a barrel). Accordingly, various embodiments of a slide assembly may include gas compensation and/or an alignment system.
Slide assembly with optic mounting platform [0097] Pistols may be retrofitted with a red dot sight using an MOS (modular optic system) using a mount bracket located behind the ejection port. FIG. 1B illustrates a partial top view of a slide with an MOS (modular optic system) cover plate removed. The slide 150 may otherwise be similar to the slide 100 (FIG. 1A). FIG. 1C illustrates a bottom view of an MOS adapter plate 151 (the MOS adapter plate is an intermediary interface to couple to an optic adapter mounting interface ¨ other optic adapter mounting interfaces exist). FIG. 1D
illustrates a slide assembly 152 in which the MOS adapter plate 151 of FIG. 1C is installed on the slide of FIG. 1B.
[0098] FIG. lE illustrates installation of a sealing plate 153 on the slide assembly 152 of FIG.
1D. The sealing plate 153 may be made out of thin sheet metal. The sealing plate 153 may have a width that is the same as a width of a bottom of an RMR optic 154 (FIG. IF
illustrates a bottom view of an RMR optic 154), both of which may be wider than the MOS adapter plate 151 (FIG.

1C). The sealing plate 153 forms a seal with a seal 156 to prevent moisture from reaching the battery 155. FIG. 1G illustrates the RMR optic 154 of FIG. 1F and the sealing plate 153 of FIG.
lE installed on the slide assembly of FIG. 1D.
[0099] FIG. 11A illustrates top and side views of a slide 1100 including an optic mounting platform 1153 integrally formed on the top of the slide 1100 and a grip for charging the slide integrally formed from sides 1155 below the optic mounting platform 1153. FIG.
11B illustrates a partial side view of the slide 1100 of FIG. 11A. FIG. 11C illustrates the slide 1100 of FIGS.
11A-B being charged using the grip that is integrally formed from the sides 1155 below the optic mounting platform 1153.
[00100] Referring to FIG. 11A, in this embodiment, the width of the optic mounting platform 1153 corresponds to the width of the RMR optic 154 (FIG. 1F). FIG. 13 illustrates a partial side view of a slide assembly in which the RMR optic 154 illustrated in FIG. IF is mounted directly on the slide 1100, and in which the sides of the RMR optic 154 align with sides of the optic mounting platform 1153. Other embodiments may be arranged for use with some other optic, and the sides of the optic mounting platform 1153 align with the sides of the optic.
[00101] Referring again to FIG. 11A, the RMR optic 154 may mount directly on the optic mounting platform 1153. The optic mounting platform 1153 includes a smooth surface to form a seal with the seal 156 (FIG. 11C) of the RMR optic 154 in the case of direct mounting. In some embodiments, a distance between a surface of the optic mounting platform 1153 and the top of the RMR optic 154 may be less than a distance between a top of the slide 150 (FIG.
1B) and the RMR
optic 154, reducing the height of the firearm assembly.
[00102] In this embodiment, the optic mounting platform 1153 is a recess in a top of the slide 1100. In particular, material is removed from the top of the slide 1100 to form the surface of the optic mounting platform. In this embodiment, the surface of the optic mounting platform 1153 is lower than a top of the slide 1100 in front and/or behind the optic mounting platform 1153. As such, a distance between the surface of the optic mounting platform and the top of the RMR optic 154 may be less than a thickness of a stack including the MOS adapter plate 151 (FIG. 1C) and/or the sealing plate 153 (FIG. 1E). In other embodiments, the optic mounting platform 1153 may be formed using other techniques besides recessing a top of the slide. Whether or not recessing is used, in various embodiments the surface of the top of the optic mounting platform 1153 may be arranged to be no greater than surfaces of a top of the slide in front and/or behind the optic mounting platform 1153 (e.g., lower than or coplanar with the surfaces of the top of the slide in front and/or behind the optic mounting platform 1153).
[00103] The sides of the slide 150 (FIG. 1B) include scalloping to grip the vertical sidewalls of the slide 150 to charge the slide 150. However, when the slide gets wet and/or if the user does not grip the slide optimally (say, due to an injury), the user's grip may slip before completely charging the slide.
[00104] Referring to FIG. 11A, the sides 1155 slope inward from an edge of the optic mounting platform 1153 to a lower location on the sides 1155. This provides an increasing width of the slide 1100 towards the optic mounting platform 1153). This increasing width gives the user leverage when gripping the slide 1100 to compensate for non-optimal conditions (e.g., wet equipment, or an injured hand).
[00105] In this embodiment, the inward slope is a continuous linear slope. In other embodiments, the sides 1155 may have a non-linear slope and/or may have varying slopes (for instance two or more slopes may be used to provide an angular surface). In various embodiments, the sides 1155 may have indentions (such as the scalloping of the slide 150 in FIG. 1B or some other indentation such as the triangular depression shown in FIG. 13) or bumps, as desired, to optimize the leverage associated with this grip point.
[00106] FIG. 11D illustrates a back view of a slide assembly in an embodiment in which the exterior sides of the slide are inward sloping from an upper location 1195 below the optic mounting platform 1193 to a lower location below the upper location 1194. Optic mounting platform 1193 may be similar in any respect to optic mounting platform 1153 (FIG. 11A).
[00107] In this embodiment, a relief cavity 1199 is created by removing some material from a portion of the inward sloping exterior side. Other examples may not include the relief cavity 1199.
Another embodiment may use a continuous non-linear slope. In yet other embodiments, the exterior sides may include varying slopes (linear slopes, non-linear slopes, or combinations thereof).

[00108] FIG. 11E illustrates a back view of a slide assembly in another embodiment including an optical mounting platform 1197 overhanging fully vertical exterior surfaces 1192 of sides of the slide. The optical mounting platform 1197 may be similar to optical mounting platform 1193 (FIG. 11D) in any respect. In this embodiment, an upper portion of the exterior surface of the sides of the slide has two different inward slopes above the fully vertical exterior surface 1192. In other embodiments, there may be a single continuous slope above fully vertical exterior surfaces 1192 (and this single continuous slope may be linear or non-linear). In other embodiments, there may be no inward sloping (e.g., the sidewall section above fully vertical exterior surfaces 1192 may include only one or more fully horizontal sections and one or more fully vertical sections, e.g., one or more "steps").
Optic Guard [00109] Referring again to FIG. 11A, this embodiment of the slide 1100 includes an optic guard mount 1170 in front of the optic mounting platform 1153. In this embodiment, the optic guard platform 1153 is integrally formed with the slide 1100 (e.g., integrally formed with the top and/or sides 1155 of the slide 1100). In this embodiment, the optic guard mount 1170 is a groove (e.g., a dovetail groove). A plug 1160 is shown installed in the dovetail groove in FIG. 11B. In other embodiments, an optic guard mount similar to optic guard mount 1170 may be provided in a firearm assembly that may or may not include the optic mounting platform 1153.
[00110] Referring to FIG. 12, an optic guard 1200 is shown installed in the optic guard mount 1170. The optic guard 1200 includes a mounting section 1201 to mate with the optic guard mount 1170, and a frame 1205 coupled to the mounting section 1201. In this embodiment, the frame 1205 protects a lens of the RMR optic 154, and a housing of the RMR optic 154 (e.g., the housing on the optic mounting platform 1153). The frame 1205 may protect the top and sides of the housing of the RMR optic 154.
[00111] In this embodiment, the mounting section 1201 couples to a firearm assembly independently of the housing of the RMR optic 154. In the present embodiment, the mounting section 1201 couples directly to a firearm. In another embodiment, the mounting section 1201 may couple to the firearm assembly by piggyback-mounting to an optic that is mounted on the firearm. For example, the firearm assembly may include a long range optic mounted on the firearm and a short range optic mounted on the long range optic.
[00112] In this embodiment, the optic guard 1200 is arranged to couple to the firearm assembly without contacting the optic and without contacting the housing thereof (e.g., in this embodiment - without contacting any part of the RMR optic 154). A gap between a back of the frame 1205 and the housing of the RMR optic 154 is shown. The gap also prevents impact to the optic guard 1200 from transferring energy to the RMR optic 154 - reducing risk of damage to the optic (and also maintaining zero of the sight alignment).
[00113] The RMR optic 154 may be sighted in at a time of installation of the optic guard 1200.
The arrangement of the optic guard mount 1170 may provide for installation without any contact between the optic guard 1200 and, in this example, any part of the RMR optic 154. For instance, the dovetail groove embodiment of the optic guard mount 1170 allows the optic guard 1200 to be side-installed to maintain zero of the slight alignment of the firearm assembly (no contact with RMR optic 154 during installation).
[00114] In the illustrated embodiment, the frame 1205 is fully-enclosed ¨ it includes a top frame segment, a bottom frame segment, and side frame segments (e.g., four sided).
In other examples, a frame of on optics guard may have a fewer or greater number of sides (such as a ring shape) and/or be fully and/or substantially enclosed to protect a top and sides of a housing of an optic.
[00115] A front of at least one frame segment of the frame segments may include indentations/bumps forming another grip location for charging the slide (the indentations/bumps may also be provided on other frame members, such as on a top part of the front of the side frame segments). One embodiment of the frame 1205 is similar to the frame of the optic guard bracket shown in FIG. 15 (in which indentations are provided on the frame members of the optic guard bracket illustrated in FIG. 15). Charging using this grip location may be performed using the palm of the hand, as illustrated in FIG. 14D. Due to the gap and the depth of the frame 1205, charging using this grip location may not smudge the optic (and as already mentioned may maintain zero).
[00116] FIG. 13 illustrates a partial side view of an optic guard with an integrated rear sight 1399.
This optic guard may be similar in any respect to optic guard 1200 (FIG. 12).
In this embodiment,

17 the integrated rear sight 1399 is located on a bottom member of the frame of optic guard 1200. In another embodiment, the integrated rear sight 1399 may be provided on some other part of the optic guard 1200. In some embodiments, the integrated rear sight 1399 may be releasably coupled to the optics guard 1200. The integrated rear sight 1399, and the charging grip points, are usable regardless of whether the firearm is currently provisioned with an optic or not.
Optic Guard with Integrated Bracket [00117] FIG. 14A illustrates a side view of an optic guard 1400 usable with the slide 100 and the RMR optic 154 shown in FIG. 1F. This optic guard 1400 includes a frame 1415 (which may be similar in any respect to the frame 1205 of FIG. 12). The frame 1415 is fixably attached to a front of a bracket 1410. Fixable attachment may be welding one or more protrusions on the front of the bracket 1410 or the frame 1415 into mating openings formed on the other of the front of the bracket 1410 and the frame 1415 (e.g., non-releasably attached). FIG. 15 illustrates another embodiment of an optic guard 1500 usable on a legacy slide in which the optic guard 1500 has a fully-enclosed frame fixably attached to a bracket in which the front-most openings 1505 on the bottom of the front of the bracket expose protrusions 1510 extending from the bottom of the frame.
[00118] Referring again to FIG. 14A, in this embodiment the bracket 1410 is a plate. However, in other embodiments, a bracket need not be a plate (this is shown in FIG. 15, in which the bracket has a front section that is thicker than a rear section of the bracket).
[00119] Referring again to FIG. 14A, a surface of the top side of the bracket 1410 may be similar in any respect to the surface of the mounting platform 1153 (FIG. 11A). The bottom side of the bracket 1410 may be smaller than the top side, and may similar to the bottom of the MOS adapter plate 151 (FIG. 1C). FIG. 14B illustrates that the sides 1420 of the bracket 1410 may be sloped, although this is not required.
[00120] FIG. 14C illustrates a partial side view of a firearm including the optic guard 1400 (FIG.
14A) with the RMR optic 154 (FIG. 1F) installed thereon. The gap between the back of the frame of the optic guard 1400 and the front of the housing of the RMR optic 154 may be the same as the gap described with respect to FIG. 12.

18 [00121] FIG. 14D illustrates charging a slide using a grip location provided on an optic guard.
Charging may be accomplished without bumping the RMR optic 154 and without smudging the optic thereof. This charging grip point does not require the use of fingers/thumb (the scalloped grip on the side of the slide 100 of FIG. 1 A is gripped using a finger and thumb). This charging grip point may be gripped using the palm instead, allowing the slide to be optimally charged (e.g., charged without smudging the optic and/or without bumping the RMR optic 154) -even in the case of an injury to the finger or thumb.
[00122] Referring again to FIG. 15, this optic guard 1500 with integrated bracket may be utilized with a different legacy slide than the legacy slide 100 of FIG. 1A. The underside of the bracket is arranged for attaching to a top exterior surface of the legacy slide. The top surface of the bracket (not shown) may be similar in any respect to the top surface of the mounting platform 1153 (FIG.
11A).
[00123] Having described and illustrated various examples herein, it should be apparent that other examples may be modified in arrangement and detail, e.g.:
= Any slide assembly described herein may be arranged to include any optic mounting platform described herein and/or arranged to include any optic guard mount described herein, according to various embodiments. Any slide assembly described herein may be arranged to include any alignment system described herein, according to various embodiments. Any slide assembly described herein may be arranged to retrofit a firearm having a slide assembly or may be part of original equipment of a firearm, according to various embodiments.
= The optic guards and the optic guard brackets described herein may be arranged to interoperate with any slide assembly described herein, or some other slide assembly currently known or later developed, according to various embodiments.
[00124] We claim all modifications and variations coming within the spirit and scope of the following examples.

19 EXAMPLES
Examples "Al+" Slide assembly to provide gas compensation to reduce recoil Examples "B1+" Slide assembly with optic mounting platform Examples "C1+" Optic guard to mount on a firearm assembly (e.g., to mount directly to a firearm or to piggyback mount on an accessory thereof) Examples "D1+" Optic guard bracket Examples "E1+" Slide assembly with alignment system Al. A retrofit assembly for a firearm, the retrofit assembly to provide the firearm with gas compensation to reduce recoil, the retrofit assembly comprising:
a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end, and wherein an upper region of the bore length segment includes an egress for gas propelled from a chamber inside the barrel hood segment;
a slide around the barrel, the slide including a barrel hood channel to receive the barrel hood segment through a range of motion of the slide relative to the barrel responsive to a firing of the firearm, wherein the barrel hood channel is defined by a length of interior surfaces of a top and sides of the slide; and the slide further including an opening in the slide, the opening to expose the egress of the bore length segment of the barrel;

wherein the interior surfaces of the top and sides of the slide further define an arch in front of the barrel hood channel, wherein a front surface of the arch is behind or aligned with the egress of the barrel.
A2. The retrofit assembly of example Al, wherein an underside of the arch is arranged to slidingly engage the upper region of the bore length segment in part of the range of motion.
A3. The retrofit assembly of example Al, wherein a profile of an underside of the arch corresponds to a profile of the upper region of the bore length segment of the barrel.
A4. The retrofit assembly of example A3, wherein a slope of the underside of the arch is non-linear.
A5. The retrofit assembly of example A3, wherein a portion of a slope of the underside of the arch is linear.
A6. The retrofit assembly of example A3, wherein the profiles comprise curves having a same degree of curvature.
A7. The retrofit assembly of example Al, wherein the front surface of the arch forms a gas port with the egress to guide the gas in a direction that provides the gas compensation to reduce the recoil.

A8. The retrofit assembly of example A7, wherein the opening forms the gas port with the front surface of the arch and the egress.
A9. The retrofit assembly of example A8, further comprising a group of through openings in sidewalls of the gas port, wherein each through opening has a first end on a surface of one of the sidewalls of the gas port and a second end on an exterior of a corresponding side of the sides of the slide.
A10. The retrofit assembly of example Al, wherein the egress comprises one or more openings in the barrel, and wherein the opening in the top of the slide comprises a single contiguous opening or a plurality of openings.
All. The retrofit assembly of example Al, wherein the top of the slide defines an additional opening for a sight, wherein the additional opening for the sight located behind the arch.
Al2. The retrofit assembly of example Al, wherein the top of the slide defines a window located behind the arch, the window to expose the upper region of the bore length segment of the barrel.
A13. The retrofit assembly of example Al, wherein a portion of a bore of the bore length segment is smooth, the smooth portion of the bore located between the egress and the muzzle end of the bore.

A14. The retrofit assembly of example Al, wherein an edge transition between the egress and the bore comprises a chamfer.
A15. The retrofit assembly of example Al, further comprising a circumferential groove on the bore of the bore length segment, wherein the circumferential groove corresponds with an edge of the egress.
A16. The retrofit assembly of example A15, wherein the circumferential groove comprises sloped sidewalls.
A17. The retrofit assembly of example A15, wherein the circumferential groove comprises side surfaces and a bottom surface, wherein the side surfaces comprise sloped sidewalls.
A18. The retrofit assembly of example Al, the barrel length segment is non-cylindrical and an upper surface of the barrel length segment comprises one of a protrusion or groove to mate with a groove or protrusion defined by an underside of the arch.
A19. The retrofit assembly of example Al, wherein the upper section of the bore length segment further defines a sight tracker located proximate to the egress.
A20. The retrofit assembly of example A19, wherein the sight tracker defines an additional egress.
A21. A firearm, comprising:

a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end, and wherein an upper region of the bore length segment includes an egress for gas propelled from a chamber inside the barrel hood segment; and a slide around the barrel, the slide including a barrel hood channel to receive the barrel hood segment through a range of motion of the slide relative to the barrel responsive to a firing of the firearm, wherein the barrel hood channel is defined by a length of interior surfaces of a top and sides of the slide;
the slide further including an opening in the slide, the opening to expose the egress of the bore length segment of the barrel; and wherein the interior surfaces of the top and sides of the slide further define an arch in front of the barrel hood channel, wherein a front surface of the arch is behind or aligned with the egress of the barrel.
A22. The firearm of example A21, further comprising any of the features of the retrofit assembly of any of examples A1-A21.
B1. An apparatus, comprising:
a slide having a top and sides;
an optic mounting platform integrally formed from at least the top of the slide; and a grip for charging the slide, the grip integrally formed from sloped exteriors of the sides of the slide, the sloped exteriors located beneath the optic mounting platform, wherein each sloped exterior is =
sloped inward from a first upper location on the sloped exterior to a second location below the first upper location on the sloped exterior.

B2. The apparatus of example Bl, wherein the apparatus comprises a firearm or a firearm retrofit assembly.
B3. The apparatus of example Bl., further comprising:
an optic guard mount integrally formed from the top or sides of the slide.
B4. The apparatus of example B3, further comprising an optic guard installable using the optic guard mount, wherein the optic guard includes:
a mounting section to mate with the optic guard mount; and a frame on the mounting section, the frame arranged to protect an optic installed on the optic mounting platform and a top and sides of a housing of the optic.
B5. The apparatus of example B4, wherein the frame includes frame segments including a top frame segment, a bottom frame segment, and side frame segments, wherein at least one of the frame segments includes grip indentions or grip bumps for charging the slide using the optic guard.
B6. The apparatus of example B5, wherein the frame is a fully-enclosed frame.
B7. The apparatus of example Bl, wherein the optic mounting platform is arranged to form a sealed enclosure with a housing of a powered optic, wherein the optic mounting platform includes mounting holes surrounded by a smooth surface, the smooth surface to directly contact a seal of the powered optic.

B8. The apparatus of example B1, wherein each sloped exterior comprises a continuous linear slope or a continuous non-linear slope.
B9. The apparatus of example B1, wherein each sloped exterior comprises varying slopes.
B10. The apparatus of example B9, wherein each sloped exterior has a section with a non-linear slope.
B11. The apparatus of example B1, further comprising a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end;
wherein an underside of the top of the slide defines a protrusion or groove to align with a groove or protrusion on the bore length segment to restrict movement of the muzzle end of the barrel within a plane perpendicular to a bore axis of the barrel and prevent rotational movement of the barrel relative to the slide.
B12. An apparatus, comprising:
a slide having a top and sides;
an optic mounting platform integrally formed from at least the top of the slide;
wherein the optic mounting platform includes a front end, a rear end, and sides:
wherein the sides of the optic mounting platform overhang exterior surfaces of the sides of the slide; and wherein a top surface of the optic mounting platform comprises a recess in the top of the slide or the top surface of the optic mounting platform is lower than or coplanar with a section of the top of the slide, wherein the section is located in front of the front of the optic mounting platform or behind a back of the optic mounting platform.
313. The apparatus of example B12, further comprising a grip for charging the slide, the grip integrally formed from the exterior surfaces of the sides of the slide.
B14. The apparatus of example B12, wherein surfaces of the sides of the optic mounting platform are orthogonal with the top surface of the optic mounting platform.
B15. The apparatus of example B12, further comprising a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end;
wherein an underside of the top of the slide defines a protrusion or groove to align with a groove or protrusion on the bore length segment to restrict movement of the muzzle end of the barrel within a plane perpendicular to a bore axis of the barrel and prevent rotational movement of the barrel relative to the slide.
B16. The apparatus of any of examples B1-B15, wherein the slide is the slide of the retrofit assembly or firearm of any of examples A1-A22.
Cl. An apparatus, comprising:
an optic guard to protect an optic of a firearm assembly and the housing of said optic, the optic guard including:

a mounting section to couple to a firearm assembly independently of the housing of said optic; and a frame on the mounting section, the frame arranged to protect the optic and top and sides of the housing of said optic;
wherein the optic guard is arranged to couple to the firearm assembly without contacting the optic and without contacting the housing of said optic.
C2. The apparatus of example Cl, wherein the optic of the firearm assembly is arranged to piggyback-mount on an optic mountable on a firearm of the firearm assembly, and wherein the mounting section is arranged to separately piggyback mount to the optic mountable on the firearm.
C3. The apparatus of any of examples Cl-C2, wherein the firearm assembly includes a slide assembly having any of the features of examples Al-B16.
Dl. An optic guard for a firearm assembly, the optic guard comprising:
a bracket having a first side to attach to an optic adapter mounting interface of the firearm assembly, a second side that is opposite the first side, the second side defining an optic attachment, wherein the optic guard is arranged to protect an optic installed using the optic attachment and a top and sides of a housing of the optic;
the bracket having a front section and a back section; and a frame integrally formed with the front section of the bracket or fixably attached to the front section of the bracket.

D2. The optic guard of example D1, wherein the bracket comprises a plate, wherein the first side comprises a first side of the plate and the second side comprises a second side of the plate, wherein the front section includes a front edge of the plate and theback section includes a back edge of the plate, wherein the plate has sloped side edges, the sloped side edges inwardly sloping from an edge of the second side of the plate to an edge of the first side of the plate.
D3. The optic guard of example D1, wherein the frame includes frame segments including a top frame segment, a bottom frame segment, and side frame segments, wherein at least one frame segment of the frame segments includes grip indentions or grip bumps for charging a slide of the firearm using the optic guard.
D4. The optic of example D1, wherein the frame comprises a fully-enclosed frame.
D5. The optic guard of example D1, wherein a lower region of the frame is non-releasably coupled to the front section of the bracket.
D6. The optic guard of example DI., wherein the front section of the bracket defines a groove or protrusion welded to a protrusion or groove defined by the frame.
D7. The optic guard of example D1, wherein the second side of the bracket is arranged to form a sealed enclosure with a bottom of the housing of the optic, wherein the second side of the bracket includes mounting holes surrounded by a smooth surface, the smooth surface to directly contact a seal of the powered optic.

D8. The optic guard of any of examples 01-08, wherein the firearm assembly includes a slide assembly having any of the features of examples Al-B16.
El. A firearm or a firearm retrofit assembly, comprising:
a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end;
a slide around the barrel; and an alignment system to restrict movement of the muzzle end of the barrel within a plane perpendicular to a bore axis of the barrel and prevent rotational movement of the barrel relative to the slide, wherein the alignment system includes a groove or protrusion located on the bore length segment of the barrel, the groove or protrusion to mate with a protrusion or groove defined by an interior of the slide.
E2. The firearm or firearm retrofit assembly of example El, wherein the slide is the slide of any of the slide assemblies of any of examples Al-B16.
E3. The firearm or firearm retrofit assembly of example El, further comprising the optic guard of any of examples Cl-D7.

Claims

What is claimed is:
1. A retrofit assembly for a firearm, the retrofit assembly to provide the firearm with gas compensation to reduce recoil, the retrofit assembly comprising:
a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end, and wherein an upper region of the bore length segment includes an egress for gas propelled from a chamber inside the barrel hood segment;
a slide around the barrel, the slide including a barrel hood channel to receive the barrel hood segment through a range of motion of the slide relative to the barrel responsive to a firing of the firearm, wherein the barrel hood channel is defined by a length of interior surfaces of a top and sides of the slide; and the slide further including an opening in the slide, the opening to expose the egress of the bore length segment of the barrel;
wherein the interior surfaces of the top and sides of the slide further define an arch in front of the barrel hood channel, wherein a front surface of the arch is behind or aligned with the egress of the barrel.
2. The retrofit assembly of claim 1, wherein an underside of the arch is arranged to slidingly engage the upper region of the bore length segment in part of the range of motion.
3. The retrofit assembly of claim 1, wherein a profile of an underside of the arch corresponds to a profile of the upper region of the bore length segment of the barrel.

4. The retrofit assembly of claim 3, wherein a slope of the underside of the arch is non-linear.
5. The retrofit assembly of claim 3, wherein a portion of a slope of the underside of the arch is linear.
6. The retrofit assembly of claim 3, wherein the profiles comprise curves having a same degree of curvature.
7. The retrofit assembly of claim 1, wherein the front surface of the arch forms a gas port with the egress to guide the gas in a direction that provides the gas compensation to reduce the recoil.
8. The retrofit assembly of claim 7, wherein the opening forms the gas port with the front surface of the arch and the egress.
9. The retrofit assembly of claim 8, further comprising a group of through openings in sidewalls of the gas port, wherein each through opening has a first end on a surface of one of the sidewalls of the gas port and a second end on an exterior of a corresponding side of the sides of the slide.
10. The retrofit assembly of claim 1, wherein the egress comprises one or more openings in the barrel, and wherein the opening in the top of the slide comprises a single contiguous opening or a plurality of openings.

11. The retrofit assembly of claim 1, wherein the top of the slide defines an additional opening for a sight, wherein the additional opening for the sight located behind the arch.
12. The retrofit assembly of claim 1, wherein the top of the slide defines a window located behind the arch, the window to expose the upper region of the bore length segment of the barrel.
13. The retrofit assembly of claim 1, wherein a portion of a bore of the bore length segment is smooth, the smooth portion of the bore located between the egress and the muzzle end of the bore.
14. The retrofit assembly of claim 1, wherein an edge transition between the egress and the bore comprises a chamfer.
15. The retrofit assembly of claim 1, further comprising a circumferential groove on the bore of the bore length segment, wherein the circumferential groove corresponds with an edge of the egress.
16. The retrofit assembly of claim 15, wherein the circumferential groove comprises sloped sidewalls.

17. The retrofit assembly of claim 15, wherein the circumferential groove comprises side surfaces and a bottom surface, wherein the side surfaces comprise sloped sidewalls.
18. The retrofit assembly of claim 1, the barrel length segment is non-cylindrical and an upper surface of the barrel length segment comprises one of a protrusion or groove to mate with a groove or protrusion defined by an underside of the arch.
19. The retrofit assembly of claim 1, wherein the upper section of the bore length segment further defines a sight tracker located proximate to the egress.
20. The retrofit assembly of claim 19, wherein the sight tracker defines an additional egress.
21. A firearm, comprising:
a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end, and wherein an upper region of the bore length segment includes an egress for gas propelled from a chamber inside the barrel hood segment; and a slide around the barrel, the slide including a barrel hood channel to receive the barrel hood segment through a range of motion of the slide relative to the barrel responsive to a firing of the firearm, wherein the barrel hood channel is defined by a length of interior surfaces of a top and sides of the slide;

the slide further including an opening in the slide, the opening to expose the egress of the bore length segment of the barrel; and wherein the interior surfaces of the top and sides of the slide further define an arch in front of the barrel hood channel, wherein a front surface of the arch is behind or aligned with the egress of the barrel.
22. An apparatus, comprising:
a slide having a top and sides;
an optic mounting platform integrally formed from at least the top of the slide; and a grip for charging the slide, the grip integrally formed from sloped exteriors of the sides of the slide, the sloped exteriors located beneath the optic mounting platform, wherein each sloped exterior is sloped inward from a first upper location on the sloped exterior to a second location below the first upper location on the sloped exterior.
23. The apparatus of claim 22, wherein the apparatus comprises a firearm or a firearm retrofit assembly.
24. The apparatus of claim 22, further comprising:
an optic guard mount integrally formed from the top or sides of the slide.
25. The apparatus of claim 24, further comprising an optic guard installable using the optic guard mount, wherein the optic guard includes:
a mounting section to mate with the optic guard mount; and a frame on the mounting section, the frame arranged to protect an optic installed on the optic mounting platform and a top and sides of a housing of the optic.
26. The apparatus of claim 25, wherein the frame includes frame segments including a top frame segment, a bottom frame segment, and side frame segments, wherein at least one of the frame segments includes grip indentions or grip bumps for charging the slide using the optic guard.
27. The apparatus of claim 26, wherein the frame is a fully-enclosed frame.
28. The apparatus of claim 22, wherein the optic mounting platform is arranged to form a sealed enclosure with a housing of a powered optic, wherein the optic mounting platform includes mounting holes surrounded by a smooth surface, the smooth surface to directly contact a seal of the powered optic.
29. The apparatus of claim 22, wherein each sloped exterior comprises a continuous linear slope or a continuous non-linear slope.
30. The apparatus of claim 22, wherein each sloped exterior comprises varying slopes.
31. The apparatus of claim 30, wherein each sloped exterior has a section with a non-linear slope.

32. The apparatus of claim 22, further comprising a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end;
wherein an underside of the top of the slide defines a protrusion or groove to align with a groove or protrusion on the bore length segment to restrict movement of the muzzle end of the barrel within a plane perpendicular to a bore axis of the barrel and prevent rotational movement of the barrel relative to the slide.
33. An apparatus, comprising:
a slide having a top and sides;
an optic mounting platform integrally formed from at least the top of the slide, wherein the optic mounting platform includes a front end, a rear end, and sides:
wherein the sides of the optic mounting platform overhang exterior surfaces of the sides of the slide; and wherein a top surface of the optic mounting platform comprises a recess in the top of the slide or the top surface of the optic mounting platform is lower than or coplanar with a section of the top of the slide, wherein the section is located in front of the front of the optic mounting platform or behind a back of the optic mounting platform.
34. The apparatus of claim 33, further comprising a grip for charging the slide, the grip integrally formed from the exterior surfaces of the sides of the slide.

35. The apparatus of claim 33, wherein surfaces of the sides of the optic mounting platform are orthogonal with the top surface of the optic mounting platform.
37. The apparatus of claim 33, further comprising a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end;
wherein an underside of the top of the slide defines a protrusion or groove to align with a groove or protrusion on the bore length segment to restrict movement of the muzzle end of the barrel within a plane perpendicular to a bore axis of the barrel and prevent rotational movement of the barrel relative to the slide.
38. A firearm or a firearm retrofit assembly, comprising:
a barrel having a muzzle end, a breech end, and a length, wherein the length includes a barrel hood segment proximate to the breech end and a bore length segment proximate to the muzzle end;
a slide around the barrel; and an alignment system to restrict movement of the muzzle end of the barrel within a plane perpendicular to a bore axis of the barrel and prevent rotational movement of the barrel relative to the slide, wherein the alignment system includes a groove or protrusion located on the bore length segment of the barrel, the groove or protrusion to mate with a protrusion or groove defined by an interior of the slide.