US3161979A - Adjustable shotgun choke device - Google Patents

Adjustable shotgun choke device Download PDF

Info

Publication number
US3161979A
US3161979A US130905A US13090561A US3161979A US 3161979 A US3161979 A US 3161979A US 130905 A US130905 A US 130905A US 13090561 A US13090561 A US 13090561A US 3161979 A US3161979 A US 3161979A
Authority
US
United States
Prior art keywords
sleeve
choke
fingers
slots
shoulder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US130905A
Inventor
Charles E Lowe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HARTFORD GUN CHOKE CO Inc
Original Assignee
HARTFORD GUN CHOKE CO Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HARTFORD GUN CHOKE CO Inc filed Critical HARTFORD GUN CHOKE CO Inc
Priority to US130905A priority Critical patent/US3161979A/en
Application granted granted Critical
Publication of US3161979A publication Critical patent/US3161979A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41WEAPONS
    • F41AFUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE
    • F41A21/00Barrels; Gun tubes; Muzzle attachments; Barrel mounting means
    • F41A21/32Muzzle attachments or glands
    • F41A21/40Chokes for shotguns, e.g. automatic chokes
    • F41A21/42Chokes for shotguns, e.g. automatic chokes manually adjustable

Definitions

  • the present invention relates to adjustable shotgun choke devices.
  • adjustable choke devices have been well accepted as they enable a single barrel shotgun to be quickly and easily adapted to meet the requirements of all types of shooting by varying the amount of choke. These devices are commonly provided with slots arranged and disposed so that they have the added advantage of functioning to reduce the recoil. It has been recognized that chokes affect shot patterns and the general objective of this invention is to provide shotgun choke devices that enable better shot patterns and shorter shot strings to be obtained with greater uniformity regardless 'of the choke setting.
  • a shotgun choke device including a tubular element attachable at one end to the muzzle of a shotgun barrel and having, at its other end, a plurality of forwardly disposed resilient choke lingers which are circumferentially spaced to provide intermediate slots.
  • a sleeve is threaded on the element and has a forwardly and inwardly tapering shoulder engageable with the lingers as the sleeve is threaded on the elements and the shoulder is operative to force the ends of the ngers inwardly.
  • the sleeve has a plurality of apertures overlying the slots in the element and operative, in any setting 'of the choke device, to vent the barrel rearwardly of but closelyadjacent the shoulder of the sleeve.
  • Such venting being in the choke area, results in improved patterns and shorter shot strings being uniformly attained regardless of the choke setting.
  • FIGURE 1 is a side elevation of a choke device in accordance with the invention shown as installed on the muzzle of a shotgun barrel with the device adjusted for one position of use, i
  • FIGURES 2, 3, and 4 are sections taken approximately along the indicated lines 2 2, 3 3, and 4 4, respectively, of FIGURE 1,
  • FIGURE 5 is a View similar to FIGURE l but illustrating another embodiment of the invention and adjusted for another position of use
  • FIGURE 6 is a side elevation of a sleeve that may be vused in place of the sleeve of the device shown in FIGURES l through 4, and,
  • FIGURE 7 is a section taken approximately along the indicated lines 7 7 of FIGURE 6.
  • a tubular element 10 is threaded onto the muzzle of a shotgun barrel 11 and has a front sight 12.
  • the element 10 has an intermediate, exteriorly threaded portion 13 of reduced diameter and a front portion provided with a plurality of circumferen t i ally spaced, longitudinally disposed, open-ended slots 14 defining a series of forwardly disposed, resilient choke lingers 15 of arcuate cross section with each linger shown as having a forwardly and inwardly tapering shoulder 16.
  • a sleeve 17 has the rear part of its bore threaded as at 18 to enable it to be attached to the threaded portion 13 of the element.
  • the rear end of the sleeve bore is 3,161,979 Patented Dec. l22, 1964 counter-bored to .provide an annular skirt 19 overlying the element 10 adjacent the threaded portion 13.
  • a ring 21 of resilient stock encircles the sleeve 17 and has one end 22 inturned to extend through a hole V23 to engage with the forward part of the element 10 to function as a click detent as it yieldably catches in the slots 14 as the sleeve 17 is turned.
  • the sleeve 17 has a plurality of apertures located both forwardly and rearwardly of the sleeve shoulder 20. These are shown as ⁇ consisting of a plurality of axially spaced series of transversely disposed slots 24, each series having three slots each, preferably, of alength greater than the width of a choke finger 15 and arranged so that each overlies two element slots 14 in any choke position and with corresponding slots of alternate series in alignment.
  • One of the series of slots 24 rearwardly of the shoulder 20 is close thereto and is shown as extending therethrough in the cone rearwardly of its crest.
  • the element 10 is provided with a sleeve 17A which is identical to the sleeve 17 except that its shoulder 20A is at the forward end thereof.
  • the sleeve 17B has its slots 24B transversely disposed and arranged as a plurality of axially spaced series with the corresponding slots of each series being in alinement.
  • a tubular element attachable at one end to the muzzle of a shotgun barrel and including at the other end a plurality of forwardly disposed, resilient choke lingers, said lingers being circumferentially spaced to provide intermediate slots, the outer surface of the free extremities of each finger including a forwardly and inwardly tapering end portion,
  • a sleeve closely fitting over said lingers with its rear encl threaded on said element rearwardly of said fingers and including a forwardly and inwardly tapering, internal shoulder engageable with said linger end portions where- Y by, as said sleeve is threaded on said element, said fingers are forced inwardly and away from said sleeve to provide a choke effect and an annular space between the fingers and the sleeve, the width of said slots at the free extremities of the fingers decreasing as they are forced inwardly to increase the choke effect, said sleeve having a plurality of apertures in and rearwardly of said shoulder and overlying said element slots, the apertures in the shoulder becoming increasingly operative as Vents therefor as the choke effect increases.
  • forward sleeve portion also having a plurality of apertures.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Developing Agents For Electrophotography (AREA)

Description

"urn" United States Patent O M ce 3,161,979 ADJUSTABLE SHOTGUN CHOKE DEVICE Charles E. Lowe, West Hartford, Conn., assigner to Hartford Gun Choke Co., Inc., Newington, Conn., a corporation of Connecticut Filed Aug. 11, 1961, Ser. No. 130,905
2 Claims. (Cl. 42--79) The present invention relates to adjustable shotgun choke devices.
Among those owning semi-automatic or pump or slide action Shotguns, adjustable choke devices have been well accepted as they enable a single barrel shotgun to be quickly and easily adapted to meet the requirements of all types of shooting by varying the amount of choke. These devices are commonly provided with slots arranged and disposed so that they have the added advantage of functioning to reduce the recoil. It has been recognized that chokes affect shot patterns and the general objective of this invention is to provide shotgun choke devices that enable better shot patterns and shorter shot strings to be obtained with greater uniformity regardless 'of the choke setting.
In accordance with the invention, this objective is attained by providing a shotgun choke device including a tubular element attachable at one end to the muzzle of a shotgun barrel and having, at its other end, a plurality of forwardly disposed resilient choke lingers which are circumferentially spaced to provide intermediate slots. A sleeve is threaded on the element and has a forwardly and inwardly tapering shoulder engageable with the lingers as the sleeve is threaded on the elements and the shoulder is operative to force the ends of the ngers inwardly. The sleeve has a plurality of apertures overlying the slots in the element and operative, in any setting 'of the choke device, to vent the barrel rearwardly of but closelyadjacent the shoulder of the sleeve. Such venting, being in the choke area, results in improved patterns and shorter shot strings being uniformly attained regardless of the choke setting.
In the accompanying drawings, there are shown illustrative embodiments of the invention from which these and other of its objectives, novel features, and advantages will be readily apparent.
In the drawings:
FIGURE 1 is a side elevation of a choke device in accordance with the invention shown as installed on the muzzle of a shotgun barrel with the device adjusted for one position of use, i
FIGURES 2, 3, and 4 are sections taken approximately along the indicated lines 2 2, 3 3, and 4 4, respectively, of FIGURE 1,
FIGURE 5 is a View similar to FIGURE l but illustrating another embodiment of the invention and adjusted for another position of use,
FIGURE 6 is a side elevation of a sleeve that may be vused in place of the sleeve of the device shown in FIGURES l through 4, and,
FIGURE 7 is a section taken approximately along the indicated lines 7 7 of FIGURE 6.
In accordance with the invention, a tubular element 10 is threaded onto the muzzle of a shotgun barrel 11 and has a front sight 12. The element 10 has an intermediate, exteriorly threaded portion 13 of reduced diameter and a front portion provided with a plurality of circumferen t i ally spaced, longitudinally disposed, open-ended slots 14 defining a series of forwardly disposed, resilient choke lingers 15 of arcuate cross section with each linger shown as having a forwardly and inwardly tapering shoulder 16.
A sleeve 17 has the rear part of its bore threaded as at 18 to enable it to be attached to the threaded portion 13 of the element. The rear end of the sleeve bore is 3,161,979 Patented Dec. l22, 1964 counter-bored to .provide an annular skirt 19 overlying the element 10 adjacent the threaded portion 13. In the intermediate part of the bore, there is a forwardly and inwardly tapering or cone portion deiningfa shoulder 20.
It will be apparent that as the choke device is assembled by threading the sleeve 17 on the portion 13 of the element 10, the shoulders 16 and 20 engage until the ends of the fingers 15 are forced inwardly from their normal position to the desired extent. In theirnormal Iposition, the lingers 15 define a cylinder and when they are forced inwardly to the maximum extent,usually with their free ends in marginal contact, a full choke position is effected. Desired intermediate choke positions are provided such as so-called improved and modified positions. Additional positions are also provided, one between each successive two of the above referred to major positions. A ring 21 of resilient stock encircles the sleeve 17 and has one end 22 inturned to extend through a hole V23 to engage with the forward part of the element 10 to function as a click detent as it yieldably catches in the slots 14 as the sleeve 17 is turned. In practice, there are six slots 14 and six choke positions ranging from cylinder to full choke. These positions are marked on the sleeves (see FIGURES l and 5) and are readable with reference to the front sight 12.
The sleeve 17 has a plurality of apertures located both forwardly and rearwardly of the sleeve shoulder 20. These are shown as` consisting of a plurality of axially spaced series of transversely disposed slots 24, each series having three slots each, preferably, of alength greater than the width of a choke finger 15 and arranged so that each overlies two element slots 14 in any choke position and with corresponding slots of alternate series in alignment. One of the series of slots 24 rearwardly of the shoulder 20 is close thereto and is shown as extending therethrough in the cone rearwardly of its crest.
In the embodiment of the invention illustrated by FIG- URES 6 and 7, the element 10 is provided with a sleeve 17A which is identical to the sleeve 17 except that its shoulder 20A is at the forward end thereof. In the embodiment shown in FIGURE 5, the sleeve 17B has its slots 24B transversely disposed and arranged as a plurality of axially spaced series with the corresponding slots of each series being in alinement.
It is the rearward slots that are the most important feature of the invention. It will be noted that in any operative position of the choke device, even in the full choke position, the slots 14 are open. By providing slots rearwardly of the sleeve shoulders, gas is vented rearwardly of the ends of the lingers 15 which define the muzzle of the barrel. While the impingement of gas streams on the leading walls of the transverse sleeve slots is effective to reduce recoil, the venting of the choke area results in important improvement in shot patterns and shorter shot strings since it minimizes the effect of the choke on the gas streams passing therethrough.
I claim:
1. In a shotgun choke device, a tubular element attachable at one end to the muzzle of a shotgun barrel and including at the other end a plurality of forwardly disposed, resilient choke lingers, said lingers being circumferentially spaced to provide intermediate slots, the outer surface of the free extremities of each finger including a forwardly and inwardly tapering end portion,
and a sleeve closely fitting over said lingers with its rear encl threaded on said element rearwardly of said fingers and including a forwardly and inwardly tapering, internal shoulder engageable with said linger end portions where- Y by, as said sleeve is threaded on said element, said fingers are forced inwardly and away from said sleeve to provide a choke effect and an annular space between the fingers and the sleeve, the width of said slots at the free extremities of the fingers decreasing as they are forced inwardly to increase the choke effect, said sleeve having a plurality of apertures in and rearwardly of said shoulder and overlying said element slots, the apertures in the shoulder becoming increasingly operative as Vents therefor as the choke effect increases.
2. The choke device of claim 1 in which the sleeve includes a forward portion the inside diameter of which is that of the forward extremity of the shoulder, the
forward sleeve portion also having a plurality of apertures.
References Cited in the file of this patent UNITED STATES PATENTS 1,892,522 White Dec. 27, 1932 2,656,637 Richards Oct. 27, 1953 2,662,326 Powell Dec. 15, 1953 2,663,961 White Dec. 29, 1953 2,759,286 Moore Aug. 21, 1956 2,977,702 Schacht Apr. 4, 1961 2,989,815 Hare .Tune 27, 1961

Claims (1)

1. IN A SHOTGUN CHOKE DEVICE, A TUBULAR ELEMENT ATTACHABLE AT ONE END TO THE MUZZLE OF A SHOTGUN BARREL AND INCLUDING AT THE OTHER END A PLURALITY OF FORWARDLY DISPOSED, RESILIENT CHOKE FINGERS, SAID FINGERS BEING CIRCUMFERENTIALLY SPACED TO PROVIDE INTERMEDIATE SLOTS, THE OUTER SURFACE OF THE FREE EXTREMITIES OF EACH FINGER INCLUDING A FORWARDLY AND INWARDLY TAPERING END PORTION, AND A SLEEVE CLOSELY FITTING OVER SAID FINGERS WITH ITS REAR END THREADED ON SAID ELEMENT REARWARDLY OF SAID FINGERS AND INCLUDING A FORWARDLY AND INWARDLY TAPERING, INTERNAL SHOULDER ENGAGEABLE WITH SAID FINGER END PORTIONS WHEREBY, AS SAID SLEEVE IS THREADED ON SAID ELEMENT, SAID FINGERS ARE FORCES INWARDLY AND AWAY FROM SAID SLEEVE TO PROVIDE A CHOKE EFFECT AND AN ANNULAR SPACE BETWEEN THE FINGERS AND THE SLEEVE, THE WIDTH OF SAID SLOTS AT THE FREE EXTREMITIES OF THE FINGERS DECREASING AS THEY ARE FORCED INWARDLY TO INCREASE THE CHOKE EFFECT, SAID SLEEVE HAVING A PLURALITY OF APERTURES IN AND REARWARDLY OF SAID SHOULDER AND OVERLYING SAID ELEMENTS, THE APERTURES IN THE SHOULDER BECOMING INCREASINGLY OPERATIVE AS VENTS THEREFOR AS THE CHOKE EFFECT INCREASES.
US130905A 1961-08-11 1961-08-11 Adjustable shotgun choke device Expired - Lifetime US3161979A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US130905A US3161979A (en) 1961-08-11 1961-08-11 Adjustable shotgun choke device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US130905A US3161979A (en) 1961-08-11 1961-08-11 Adjustable shotgun choke device

Publications (1)

Publication Number Publication Date
US3161979A true US3161979A (en) 1964-12-22

Family

ID=22446903

Family Applications (1)

Application Number Title Priority Date Filing Date
US130905A Expired - Lifetime US3161979A (en) 1961-08-11 1961-08-11 Adjustable shotgun choke device

Country Status (1)

Country Link
US (1) US3161979A (en)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3243910A (en) * 1965-02-02 1966-04-05 Weiser Bernard Shotgun choke
US4151671A (en) * 1978-05-24 1979-05-01 Mcpeak Walter G Mechanism for remotely operating variable choke devices for shotguns
US5452535A (en) * 1993-06-04 1995-09-26 Impromark, Inc. Shotgun shell wad/shot cup retarding device
USRE35381E (en) * 1992-07-13 1996-11-26 Browning Ballistic optimizing system for rifles
US5798473A (en) * 1997-04-30 1998-08-25 Roblyer; Steven Harmonic optimization system for rifles
WO2000016031A1 (en) * 1998-09-11 2000-03-23 B.B.A. Research & Development, Inc. Shotgun choke
US6052935A (en) * 1998-07-10 2000-04-25 Remington Arms Company, Inc. Shotgun choke tube
US6128846A (en) * 1998-06-08 2000-10-10 Inpromark, Inc. Length shotgun choke tube
US6223458B1 (en) 1997-04-30 2001-05-01 Kevin Schwinkendorf Harmonic optimization technology
US20030029071A1 (en) * 1998-07-06 2003-02-13 Jukka Toivanen Extension device for shotgun
US6609324B1 (en) * 2000-11-17 2003-08-26 Henry J. Truitt, Jr. Adjustable shotgun choke device
US20040154208A1 (en) * 2003-02-12 2004-08-12 Walker Ronald N. Breeching tool
US6789343B1 (en) 2003-03-28 2004-09-14 James P. Dietrich Automatic choke system
US20080173166A1 (en) * 2007-01-23 2008-07-24 Andry Mark L Shotgun choke
US7895787B1 (en) * 2008-01-11 2011-03-01 Andry Mark L Porting feature for firearm
US8458945B2 (en) 2011-03-22 2013-06-11 Jimmy Washam, Jr. One piece progressive bore multi-staged shotgun choke system
US20140096426A1 (en) * 2012-10-04 2014-04-10 Browning Firearm choke tube
US20150192379A1 (en) * 2014-01-08 2015-07-09 Rock River Arms, Inc. Muzzle Brake For Firearm
US11333459B2 (en) * 2020-06-02 2022-05-17 Aaron Hipp Adjustable tuning device

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1892522A (en) * 1931-03-24 1932-12-27 Ezekiel F White Adjustable gun choke and method of constructing the same
US2656637A (en) * 1948-02-05 1953-10-27 Kenneth D Richards Shot patterning recoil compensator for firearms
US2662326A (en) * 1948-12-18 1953-12-15 Powell Edward Baden Shotgun muzzle device
US2663961A (en) * 1950-07-07 1953-12-29 White Madge Burnam Choke for gun barrels
US2759286A (en) * 1953-06-22 1956-08-21 Thomas S Moore Choke attachment for guns
US2977702A (en) * 1954-06-08 1961-04-04 Schacht Ewald Choke with contacting finger and sleeve surfaces of concentric arcs
US2989815A (en) * 1957-08-15 1961-06-27 Hartford Gun Choke Company Inc Automatic choke device for shotguns

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1892522A (en) * 1931-03-24 1932-12-27 Ezekiel F White Adjustable gun choke and method of constructing the same
US2656637A (en) * 1948-02-05 1953-10-27 Kenneth D Richards Shot patterning recoil compensator for firearms
US2662326A (en) * 1948-12-18 1953-12-15 Powell Edward Baden Shotgun muzzle device
US2663961A (en) * 1950-07-07 1953-12-29 White Madge Burnam Choke for gun barrels
US2759286A (en) * 1953-06-22 1956-08-21 Thomas S Moore Choke attachment for guns
US2977702A (en) * 1954-06-08 1961-04-04 Schacht Ewald Choke with contacting finger and sleeve surfaces of concentric arcs
US2989815A (en) * 1957-08-15 1961-06-27 Hartford Gun Choke Company Inc Automatic choke device for shotguns

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3243910A (en) * 1965-02-02 1966-04-05 Weiser Bernard Shotgun choke
US4151671A (en) * 1978-05-24 1979-05-01 Mcpeak Walter G Mechanism for remotely operating variable choke devices for shotguns
USRE35381E (en) * 1992-07-13 1996-11-26 Browning Ballistic optimizing system for rifles
US5452535A (en) * 1993-06-04 1995-09-26 Impromark, Inc. Shotgun shell wad/shot cup retarding device
US5798473A (en) * 1997-04-30 1998-08-25 Roblyer; Steven Harmonic optimization system for rifles
US6223458B1 (en) 1997-04-30 2001-05-01 Kevin Schwinkendorf Harmonic optimization technology
US6128846A (en) * 1998-06-08 2000-10-10 Inpromark, Inc. Length shotgun choke tube
US20030029071A1 (en) * 1998-07-06 2003-02-13 Jukka Toivanen Extension device for shotgun
US6052935A (en) * 1998-07-10 2000-04-25 Remington Arms Company, Inc. Shotgun choke tube
WO2000016031A1 (en) * 1998-09-11 2000-03-23 B.B.A. Research & Development, Inc. Shotgun choke
US6112447A (en) * 1998-09-11 2000-09-05 B.B.A. Research & Development, Inc Shotgun choke
US6609324B1 (en) * 2000-11-17 2003-08-26 Henry J. Truitt, Jr. Adjustable shotgun choke device
US20040154208A1 (en) * 2003-02-12 2004-08-12 Walker Ronald N. Breeching tool
US6782651B1 (en) * 2003-02-12 2004-08-31 Inpromarketing Corp. Breaching tool
US6789343B1 (en) 2003-03-28 2004-09-14 James P. Dietrich Automatic choke system
US20080173166A1 (en) * 2007-01-23 2008-07-24 Andry Mark L Shotgun choke
US7895787B1 (en) * 2008-01-11 2011-03-01 Andry Mark L Porting feature for firearm
US20110067284A1 (en) * 2008-01-11 2011-03-24 Andry Mark L Porting feature for firearm
US8458945B2 (en) 2011-03-22 2013-06-11 Jimmy Washam, Jr. One piece progressive bore multi-staged shotgun choke system
US20140096426A1 (en) * 2012-10-04 2014-04-10 Browning Firearm choke tube
US8978286B2 (en) * 2012-10-04 2015-03-17 Browning Firearm choke tube
US9297600B1 (en) * 2012-10-04 2016-03-29 Browning Firearm choke tube
US20150192379A1 (en) * 2014-01-08 2015-07-09 Rock River Arms, Inc. Muzzle Brake For Firearm
US9207034B2 (en) * 2014-01-08 2015-12-08 Rock River Arms, Inc. Muzzle brake for firearm
US9341426B1 (en) 2014-01-08 2016-05-17 Rock River Arms, Inc. Muzzle brake for firearm
US11333459B2 (en) * 2020-06-02 2022-05-17 Aaron Hipp Adjustable tuning device

Similar Documents

Publication Publication Date Title
US3161979A (en) Adjustable shotgun choke device
US10126085B2 (en) Muzzle device
US20170199002A1 (en) Systems and methods for a blast control device for a firearm
DE1553867A1 (en) Rifle butt
US2759286A (en) Choke attachment for guns
EP2887002B1 (en) Trigger system of a firearm
US4087930A (en) Magazine cap retaining means for tubular magazine firearms
US11397066B1 (en) Muzzle device and blast sleeve
US2442899A (en) Choke attachment for gun barrels
US2629958A (en) Shot pattern control device for shotguns
US2842024A (en) Anti-recoil gun barrels
US4268987A (en) Hand weapon for survival purposes
US9297600B1 (en) Firearm choke tube
US2092649A (en) Automatic choke for guns
US2464010A (en) Extension for automatic pistols
US2989815A (en) Automatic choke device for shotguns
US6052935A (en) Shotgun choke tube
US2360881A (en) Collapsible stock for firearms
US3543428A (en) Rifle forestock
DE202020102474U1 (en) Trigger device
US4024664A (en) Safety for rifle
US5666753A (en) Safety switch for shotgun equipped with scope
US2696995A (en) Mechanism for interconnecting gun accessories with the muzzle end portion of gun barrels
US2656638A (en) Shotgun choke
US2167173A (en) Shotgun barrel