US2543604A - Bolt-action firearm - Google Patents

Description

Feb. 27, 1951 L.. s. sxNGr-:R

BOLT ACTION FIREARM 2 Sheets-Sheet l Filed March 29, 1947 mi im INVENTOR. OU/5 5 SINGER Om .5mm

E ww L. S. SINGER BOLT ACTION FIREARM 2 Sheets-Sheet 2 .E ma w ,um NA Ws. m .m5 W,

Feb. 27, 1951 Filed March 29, 1947 Patented Feb. 27, 1.951

UNITED STAT ES FF ICE BOLT-ACTION `FYIREARIW LouisiS. Singer,` NewYork; NJ'YL ApplictibnMarO/h 1947;.Sri1 N0. '738,150

This invention relatesv to` boltt action firearms, incorporating a-short breechfbolt and a complementary. short receiver constituting what is known as avshort action, with specific improvements inthe loadingv4 portY and breech lock arrangement.

It is an object of this invention to provide a boltaction firearm with an improved. loading portfin the receiver,.so constructed as to provide direct accessibility to the rifle chamber for simpliied l manualV loading-.of the cartridge when' thev bolt-.is open and. withdrawnto the limituof its rearwardV position.

Afurther object is to provide a single shot firearm with` a` short receiver and reciprocable bolt, locking. at theheadproper, andwith a shal- IOWseatinginthe receiver to effectively dissipate gas. i'nevent of case rupture during firing;

A further object is` to provide a single shot firearm with an overalllshorter and compacted action, suited` for cartridges up to a length of 2'1/2'." inclusive.

A further object i's to provide an arrangement between the bolt, loading port' and chamber, whereby,with the bolt in its rearmost position, the locking` shoulders, recesses and chamber are directly exposed for cleaning` purposes.

With these and other objects of the invention in view, the means for their attainmentwill" be more apparent' from the following, description, taken in connection with the drawings, illustratinga-representative embodiment of the invention,

andwillA be hereinafter more fully described in the drawings, in which ;4

Fig. 1- isa" fragmentary sideV elevation'of' the rie embodying the invention;

Fig. 2` isha longitudinal cross-section ofthe rifle in` cocked" firing' position, exposing, the associated parts hidden in Fig. 1;

Fig. 3 is a sideV elevation of the receiver;`

Fig; 4is a lefth'and end view of the receiver;

Fig.` 5"i's a top' plan View of the. receiver;

Fig. 6`i`s a right handend view ofthe receiver;

Figs; 7-10 inclusiveare sectional views taken' at" corresponding lines' in Fig; 3;

Figi 11 is a sectional view taken along line |I`-I l ofFiggiBthrough the ejector mechanism, with the bolt shown retracted" to rearmost position;

Figi 12 isa fragmentary'side view of Fig. 11

showing the f bolt stop' provision; 139 is a longitudinal sectional view taken through line ISL-I3 of Fig. 11, showing the ejector mechanism with the bolt inrearmost position`ill`ustratin`g the manner ofcartridgeejection; and

Fig; 14"is a fragmentary perspective. view of the receiver showing. the loading and ejection port arrangement.

'IllerearmV 2l illustrated in. Figs. 1-v and 2 consists inthe main partsfof a stock 22, a barrel 3.3,-` a receiver 2'i,-and a breech bolt 3T, located in receiver 21. With the bolt open and retracted tol its rearmost position, a cartridge may be inserted through the loading port 3'6" into the chamberl't. When the bolt handle 23`is pushed forward and down,.twin opposed locking lugs 3la, and 3l`b at the bolt head' 38, engage and lock against the forwardl faced locking shoulders 50 and- 5l in the receiver ring 35. The cartridge rim 32d is engaged' by the extractor lip (conventional, not showm' at` the forward end`of tlie extractor. 3l, which is attached to the extractor collar. 26j The bolt 3I is centrally bored at 63, and adaptedto receive tlie rin'g', pin 29Lpropell`ed" forward by. a mainspring- SD released by means ofmthe trigger 24; pivotableon" aftrigger pinV 24d; Eje'ctor mechanism 42'is conventional, consisting of"`an' ejector figpivotableon'a pin Sti"y saidejector being4 urged upwardly into the central bo`re` 55, through a. suitable slot; by a nat spring 44, Fig; 13,' and colactswith" a slot 52' in the boltliead 38,' whenl theboltV is in its rearmost retracted position, dislodging: the cartridge through" the ejection port 36; The ejectcrspring 44 is staked in'th'e stock 22', and is'iomitted fromFigs; 11 and 12 for clarity.

The rearmost position of the bolt `is limit'edby a lip* 479e which is. an' integral part of the bolt stop49`, pivotableon a pinV 4917.` The lip 49e is urged" sideways, into the' groove" 5; bya spring 49d, through' a' suitable'aperture (notshownin the. re'ceiverwall', and' engages the rear face of the' boltlug' 31a in itsV rearward movementf A The receiver 2l', as shown in Figs. 3 and 5`, comprises a main' body of general semi-cylindricalexterior, having integral therewith' a cylindri'. cal forward end or. receiver ring 35, slotted through its'side a` loadin'gand'ejecting port 36't`o be descrbedl The receiver ring' 35`has' an enlarged bore 59; terminating rearwardly at a barrel-abutment or shouldr''; said bore 59A being.` internally threaded at 62,.for installation of barrel 33. The receiver is constructed with a longitudinal central bore' '55, forming. locking shoulders 5B and 5i atits junction withthe bolt lug recesses T4" andf15. Forwardly, the central borev 55 communicates with the enlargedfboreg. The left side of the receiver has an internal longitudinal groove 45, adapted'to receive the bolt lug 3la, saidgroove communicating forwardly with the enlarged bore 59?. An oppositely disposed longitudinal slot 'Hi throughthe bridge is adapted to receive the extractor 31- andv bolt lug 3|b.

The receiver ring 35- terminates rearwardly of the locking shoulders 5i)v and 5I in a receiver hood 35afandV 35o, top and bottom respectively. Accordingto my invention, the topportion of= the receiver 21 is transversely cut away, forming avtop wall 2lb, thetr-ansverse` cuti communicating foraway forming a bottom wall 21c, said cut communicating forwardly with the bottom portion of the receiver portion 3519, in a transverse radial cut 61, and'terminating rearwardly at two vertical ribs 60 and 6|, an integral part of the receiver. Rearwardly the transverse cut communicates with a longitudinal slot 68 between said ribs 6! and 6l and the grooves 68a and 68h which occupy oppositely disposed positions, on the bottom of the receiver; said ribs, slot and grooves terminating rearwardly atthe tang 51. The trigger mechanism, whichY is conventional, is supported between the ribs 60 and 6l on a pivot'pin 52a and consists of trigger 24, sear 52 and the sear spring 46.

The receiver is provided with a longitudinally extending and substantially rectangular loading and ejection port 36, intermediately positioned on the right hand side `of the receiver, the median axis of said port passing through the receiver axis at about 90o from vertical, and said -port cuts away a section of wall, common to receiver body 21 receiver hood 35a and receiver ring 35, to be later described.

The forward edge 40 of the 'loading port 36 is semicircular in form, and positioned slightly rearward of the barrel face 39, forward of the locking shoulders 56 and 5l, said port terminating rearwardly at the bridge 21a. The loading and ejection port 36 is laterally slotted through the side of the receiver body, the slot communicating with the central bore 55. The forward portion of the port 3B cuts away a portion of 'the receiver ring and receiver hood, said lateral slot communicating with the lug recesses 14 and 15 exposing-and making accessible the chamber 34a for manual loading, when the bolt is retracted to its rearmost position.

A top right hand side portion of the receiver ring and receiver hood 35a is vertically cut away and communicates downwardly with the port 36, providing further clearance and accessibility in manually loading the chamber. The vertical cut, forms a sidewall 35e extending longitudinally and terminates forwardly, at the forward edge 40 of the loading port, in a radial vertical cut 64. The sidewall forms an integral angular construction with the receiver ring, as shown in Fig. 9, and rearwardly terminates at the receiver hood 35a. The top portion of the receiver wall 21h is vertically cut away and communicates downwardly with the port 36 to provide ample clearance for shell ejection, the vertical cut extending longitudinally, terminating forwardly with the receiver hood 35a in a vertical radial cut 65 and terminating rearwardly at the bridge 21a..

The rearmost position of the barrel face 39 is limited by an abutment or shoulder forming an integral part of the receiver ring 35 therein, extending from the inner bottom portion of the receiver ring and terminating at its junction with the inner face ofthe sidewall 35o.

A groove 65 is cut longitudinally through the shoulder 16, to receive the extractor lip, said groove communicating rearwardly with thejorward edge 136 of the loading port. It is to be noted in Fig. 9 that the upper portion of the abutment 16a, adjacent to the upper bolt lug recess 1Q, communicates rearwardly with sidewall 35e, forming an integral construction therewith.

The top surface 55a. of the shoulder is arcuate and, besides coinciding with the periphery of the central bore 55, is adapted to receive the bolt head 38 in closed position. The rear face 1l of the abutment 10a is of tapered arcuate construction and communicates rearwardly with the bolt lug recess 15, said face terminating circumference-wise at theV forward bottom edge of the loading port. The upper and lower bolt lug recesses 14 and 15, respectively, within the receiver ring which are adapted to receive the bolt lugs, comprise an interior arc or partial bore of the same diameter as that of the enlarged bore 59 and extend through about three quarters of a circumference, communicating with the forward portion of the loading port slot, the interior arc terminating at its junction with the inner face of the sidewall 35e. The interior arc dening the lower bolt recess 15 communicates forwardly with the rear face 1l of the shoulder 16, and the interior arc defining the the upper bolt recess-14 communicates forwardly with the enlarged bore V59.

All conventional type firearms, such as the U. S. Springfield 1906 and the Mauser 98, employing a reciprocable breech bolt with twin opposed locking lugs at the bolt head, lock against locking shoulders, in a manner similar to that shown in Fig. 2. Heretofore, the conventional receiver construction employed an unslotted, fully cylindrical construction extending from the forward end of the receiver ring rearwardly to and including the receiver hood. In previous highpower bolt action, the top and central side portion of the receiver wall, between the bridge and receiver hood, is cut away by a median loading and ejection port, exposing the central bore to permit loading of ammunition into a magazine when the bolt is withdrawn to its rearmost position.V The corresponding center bottom portion of the receiver Wall is cut through into the central bore, and is adapted to receive the magazine.

In conventional receivers, when the bolt is in closed position, the bolt head is completely enclosed and deeply seated within the receiver ring. This deep seating creates a gap or dead-space condition, defined as the distance a cartridge must travel from the loading port edge to the chamber. In conventional firearms, it represents the distance from lthe edge of the receiver hood, through the central bore, past the locking lug recesses to the chamber, and is approximately one inch. When the bolt is retracted to its rearmost position, and it is desired to manually load a cartridge, accessibility to the chamber is possible only through the central bore and is limited by the receiver hood, as well Vas the wall of the receiver ring, which obstructs the thumb or fore-finger from fully seating the cartridge all the way in the chamber, without having to resort to closing the bolt in order to seat the cartridge. Where the firearm is chambered for an overall short lengthened cartridge, a tendency arises to peer under the receiver hood, to visually guide the bullet to the chamber, and to further prevent the bullet nose from battering against the barrel face, which occupies a deep recessed position within the receiver ring. The difficulty encountered in manual loading in the conventional type bolt action is overcome by the invention de` scribed in the following manner; the right hand side of the receiver ring as well as a portion of the receiver hood are cut away by the forward positioning of the loading port 36, which exposes the bolt lug recesses, locking vshoulders and the chamber. With the bolt open and retracted to its rearmost position, thel chamber is exposed and accessible through the loading port, enabling a cartridge to be inserted and fully seated in the chamber by hand, without having to resort to close the bolt in order to seat the cartridge. A cartridge manually loaded or inserted all the way into the chamber by hand is to an advantage and desirable where accuracy is paramount, and the battering effect of magazine feed on the bullet nose may be detrimental to highest accuracy. The gap or "dead space condition is greatly eliminated.

The shallow seating of the bolt head in closed position is advantageous in the event of cartridge case rupture during firing, permitting gas to escape more freely, through the extractor groove, and out the loading port, than does a deep seating bolt. There is also accessibility to the locking shoulders, lug recesses and barrel face for cleaning, when the bolt is open. In a critical analysis of breech locking arrangement, it can be noted in Figs. 2 and 3 that the lower bolt lug is fully supported by the locking shoulder 5l, as there are no cutouts behind said locking shoulder for magazine provision. The upper locking shoulder is reinforced by the side Wall 35o and the top wall 21h, which forms a continuous bridge construction, integral with the receiver body. Impact and iiring loads imposed on the locking shouders are internally distributed and dissipated through the receiver ring and receiver body, rather than dissipating totally within the receiver ring as in previous constructions. With the dead space condition and the overall length of the loading slot shortened suitably for smallsized cartridges, the overall arrangement of the rifle is shortened and compacted, eliminating to a great extent the ungainliness of a long stroke action.

Other features of this modified receiver do not constitute a part of this invention, being conventional, and do not require further description other than to point out that the portion of the receiver rearward of the bridge is constructed and adapted to receive the bolt plug 48 which is attached to the rear end of the bolt 3| by external threads mating with internal threads within the bolt bore 63. Directly rearward of the bridge may be formed the bolt handle receiving slot 62a, adapted to receive the hub of the bolt handle 23, and a longitudinal groove 13 adapted to accept the toe oi. the ring pin-nut 41. Rearwardly, the receiver terminates in the tang 51. A sear slot 12 is provided through the bottom of the receiver, to receive the lip of the sear 52. The trigger guard 25 is secured to the stock by screw 53 engaging a threaded bushing 54, and by a stock bolt 26 to the tang 51. The two stock bolts 26 serve to secure the receiver to the stock.

By this particular construction, there has been disclosed herein a firearm which is compacted, easier to load manually, with an eifective breech locking arrangement. It is not to be considered that this invention limits itself to the Specific construction described and illustrated, but it extends to all equivalent construction, falling within the scope of the appended claim, which is broadly construed.

Having described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

In a bolt action firearm, in combination, a barrel, a receiver secured to said barrel, and a breech bolt reciprocable in said receiver between a normal and a retracted position, said breech bolt having a pair of opposite lugs at its forward end, said barrel forming an abutment for said forward end when the bolt is in its normal position, said receiver being formed with a central bore for said bolt and with lateral internal recesses for said lugs, respectively, said central bore terminating at the forward end in a widened portion forming shoulders against which said lugs after rotation in said widened portion abut to prevent the retraction of the bolt, said receiver being formed with a longitudinal loading slot for placing a cartridge in the rear end of said barrel, said slot communicating with one of said lateral recesses and extending forwardly for a sufficient distance to overlie one of the spaces formed between said two lugs after rotation of said bolt, said receiver being provided with a sidewall extending beyond the said shoulders and forming one of the walls of said one lateral recess, said sidewall preventing rotation of the bolt in one sense when the bolt has been advanced into its normal position, said sidewall being cut away adjacent the major portion of said slot.

LOUIS S. SINGER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number

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