US3728939A

US3728939A - Apparatus for joining the slide-bolt and the barrel-frame of a firearm

Info

Publication number: US3728939A
Application number: US00183601A
Authority: US
Inventors: G Wilhelm
Original assignee: PLAINFIELD ORDINANCE CORP
Current assignee: PLAINFIELD ORDINANCE CORP
Priority date: 1971-09-24
Filing date: 1971-09-24
Publication date: 1973-04-24
Anticipated expiration: 1990-04-24

Abstract

A first member of at least partly tubular configuration is keyed to a solid member disposed within the tubular member by means of a lock piece. In a firearm, the tubular member, which is provided with a cut out extending generally transverse to the path of motion of the slide, will comprise the slide and the solid member, which is provided with a recess for receiving the lock piece, will comprise the bolt. The lock piece will have a size and shape at least commensurate with the combined dimensions of the slide cut out and bolt recess, which will be aligned, and will be retained in position by an axial pin having a bent over and forwardly extending spring loaded locking tab which engages the exterior of the slide. In the environment of a firearm the invention further comprises the frame having a precision barrel bedding recess and a barrel characterized by two diameters with a portion of the smaller diameter barrel section defining the barrel bedding; the remainder of the smaller diameter barrel section being circumscribed by a collar.

Description

[11] 3,723,939 Apr. 24, 1973 United States Patent Wilhelm ABSTRACT 1541 APPARATUS FOR JOINING THE SLIDE-BOLT AND THE BARREL- [57] FRAME OF A FIREARM A first member of at least partly tubular configuration is keyed to a solid member disposed within the tubular member by means of a lock piece. In a firearm, the tu- [75] Inventor: Gary Wilhelm, Hamden, Conn.

[73] Assignee: Plainfield Ordinance Corporation,

Middlesex, NJ.

, will comprise the slide and the solid the slide [22] Filed: Sept. 24, 1971 member, which is provided with a recess for receiving the lock piece, will comprise the bolt. The lock piece Appl. No.: 183,601

will have a size and shape at least commensurate with the combined dimensions of the slide cut out and bolt O 7 0 9 H5 2 c 9 45 75 9A 0 1 M54 16/4 9 4 00 Field of Search..................

L C t n I ll 00 55 [.1

gages the exterior of the slide. In the environment of a [56] References C'ted firearm the invention further comprises the frame hav- UNITED STATES PATENTS ing a precision barrel bedding recess and a barrel characterized by two diameters with a portion of the 42/7 A smaller diameter barrel section defining the barrel '89/196 bedding; the remainder of the smaller diameter barrel 747,585 12/1903 Browning............................ 1,181,416 5/1916 section being circumscribed by a collar. Primary Examiner-Stephen C. Bentley Attorney-David S. F ishman et al. 12 Claims, 4 Drawing Figures PATENTEDAFRM 1975 3,728,939

I I SHLU 2 M 2 APPARATUS FOR JOINING THE SLIDE-BOLT AND THE BARREL-FRAME OF A FIREARM BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mechanical apparatus which may be easily assembled and disassembled and wherein the components will be precisely aligned in the assembled position. More specifically, l

this invention is directed to firearms characterized by ease and economy of manufacture and a high degree of accuracy. Accordingly, the general objects of the present invention are to provide novel and improved apparatus of such character.

2. Description of the Prior Art While the present invention may be employed wherever it is desired to fasten two or more shafts securely together and be able to assemble and disassemble the thus secured elements rapidly and without tools, the invention has been found to be particularly useful in the firearms art. In firearms, and particularly in the case of self-loading and/or semi-automatic and automatic firearms, particularly of the blow back or unlocked breach type, it is often desirable to employ a two piece slide. Such a two piece slide assembly includes a slide member and a bolt and the weapon is assembled by inserting the slide onto the frame from the muzzle end and the bolt is thereafter assembled into the slide from the opposite end. In operation the slide assembly, that is the bolt and slide, move as a unit. The easiest manner ofjoining the bolt to the slide, or in fact for joining any two shafts or components, constitutes the drilling of a hole through both parts and inserting therethrough a cross pin. In the firearms art, however, the force of detonation of a cartridge and the resulting reciprocating motion of the slide assembly may result in such a cross pin becoming fatigued and thus being prone to shear. The shearing of a cross pin employed to join the bolt and slide of a pistol would result in the loose bolt being expelled from the weapon to the rear thus possibly causing severe injury.

Continuing further with a discussion of the firearms art, the desirable attributes of a hand gun include ease of assembly, without special tools, and accuracy. These attributes have previously been thought to be mutually exclusive. That is, hand gun design has previously been a compromise between maintaining good alignment between the barrel, slide and frame and facilitating the assembly and disassembly of the weapon for cleaning or other purposes.

With further respect to the accuracy of prior art weapons, those hand guns which have previously been characterized by a high degree of accuracy have also been comparatively expensive. The comparatively high expense of quality prior art hand guns is, at least in part, attributable to the design of the barrels and slides which required complex and thus expensive precision machining operations in order to obtain the requisite alignment between the barrel, slide and frame. Accordingly, the art has long desired a weapon which was comparatively inexpensive to manufacture while retaining the requisite accuracy.

As a consequence of the expense of ammunition, it has also long been desired to provide a hand gun wherein the caliber of the weapon could be changed while retaining the weight and feel thereof. Weapons of this type have been proposed for use as both service and practice weapons by law enforcement officers. While attempts have previously been made to provide weapons of changeable caliber, such prior art changeable hand guns have either been very expensive or highly inaccurate and, in any event, have not maintained constant handling characteristics with changes in caliber.

SUMMARY OF THE INVENTION The present invention overcomes the above briefly discussed and numerous other deficiencies and disadvantages of the prior art by providing a novel manner for securing together a pair of movable components; the invention being particularly well suited for use in weapons. In the environment ofa hand gun the present invention is also characterized by a high degree of accuracy and ease of assembly and disassembly. Further in the environment ofa weapon the present invention is characterized by the ability to change caliber by replacing the magazine, bolt and barrel while retaining use of the frame and slide.

In accordance with the present invention a member which is at least partially tubular is keyed to a solid member, the solid member being at least partly circumscribed by the tubular member, by means of a lock piece. Considering a firearm, the partly tubular member will be the slide and the solid member will be the bolt. The bolt is provided with a recess and the slide is provided with an aligned cut out; the cut out and recess being generally transverse to the direction of movement of the members. The lock piece is a solid body having a size and shape at least commensurate with combined dimensions of the recess and cut out whereby the reciprocating forces will be delivered from the slide to the bolt via the lock piece. Retention of the lock piece in the bolt recess is insured with a spring loaded locking pin which extends through the lock piece and coaxially of the path of motion of the bolt. The locking pin has an end portion which is bent outwardly and forwardly and which snaps into a locking groove at the exterior of the slide.

In the environment of a weapon, the present invention is also characterized by a frame having a precision machined barrel bedding recess and a unique barrel having a precisely machined bedding which cooperates with the bedding recess to insure precise alignment of the components. The barrel is characterized by the two diameters, preferably concentric, with the smaller diameter portion being located intermediate the ends of the larger diameter portion and being partly encircled by a spring loaded barrel collar. The are of the smaller diameter portion which is not enclosed within the barrel collar will define the barrel bedding.

BRIEF DESCRIPTION OF THE DRAWING The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the several figures and in which:

FIG. 1 is an exploded view of a hand gun in accordance with and embodying the features of the present invention;

FIG. 2 is a cross sectional side view of apparatus for securing a pair of components together in accordance with the invention, FIG. 2 depicting several of the elements of FIG. 1 in assembled position;

FIG. 3 is a cross sectional front view, taken along line 3-3 of FIG. 1, of the novel barrel of the weapon shown in FIG. 1; and

FIG. 4 is a perspective view of the barrel collar of FIGS. 1 and 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now to FIG. 1, a self-loading piston in accordance with and embodying the present invention is shown in an exploded view. The weapon of FIG. 1 includes, as major subassemblies, the frame 10, barrel 12, slide 14 and bolt 16. As will be described in greater detail below, slide 14 and bolt 16 will be joined together by means of a locking piece 18 and pin 20 when the weapon is assembled.

The frame subassembly includes a shelf 22, a barrel bedding recess 24 and a pair of oppositely disposed slide guide grooves 26 and associated lands. The frame subassembly provides a housing for the drive spring 28 and its associated support rod 30. Also mounted in frame subassembly 10 is the trigger mechanism 32 and it is to be noted that, in accordance with a preferred embodiment of the present invention, spring 28 and pin 30 pass through an aperture, not shown, in trigger 32 in the interest of a more compact reciprocating design. Also mounted in frame subassembly 10 is the hammer mechanism 34 and the magazine, not shown. The magazine and various other elements such as the safety mechanism, not shown, are all conventional components and thus have been omitted from the drawing in the interest of facilitating understanding of the invention. A particularly novel feature of the present invention is the design of the frame assembly which facilitates precision machining of the barrel bedding recess 24 through the expedient of a plunge cut with a horizontal milling machine. The precision recess, in combination with the unique design of barrel assembly 12 and slide assembly 14, insures precise alignment between the three subassemblies.

Considering now jointly FIGS. 1, 3 and 4, the barrel subassembly comprises the barrel and a barrel collar 36, In accordance with the present invention, the barrel is formed with two different diameters, the larger or major diameter portion being indicated at 38 and the smaller or minor diameter portion being indicated at 40. The design of the barrel with two diameters permits the barrel to be manufactured with minimum cost through employment, in the obtaining of the outer diameter, of a centerless grinding (turning) operation. Accordingly, the barrels of the present invention are less expensive, when compared to prior art devices of like character, while nevertheless being precisely dimensioned components. The larger diameter portion 38 of the barrel is provided with a rearwardly extending slot which communicates with the smaller diameter portion 40 and an extension or tongue 41 of collar 36 fits into this slot. The collar 36 is formed of spring steel and, when installed as shown in FIGS. 1 and 2, becomes a permanent part of the barrel subassembly 12. The

shoulders

42 and 44 defined by opposite ends of collar 36 will, with the barrel snapped into place in the frame, engage the top of the frame at opposite sides of the barrel bedding recess 24 and the collar 36 will thus prevent the barrel from turning. Collar 36, of course, defines an are greater than 180 and the remaining exposed section of smaller diameter portion 41) of the barrel, which defines the barrel bedding, will rest in barrel recess 24 whereby the rear end of the barrel will be supported by engagement between two precision machined surfaces. It may be noted that the forward end of the barrel could be turned down to permit the barrel to also function as the drive spring guide.

Slide subassembly 14 is machined from a single piece. The inner clearance hole for the bolt subassembly l6 and barrel subassembly 12 is drilled and reamed thus further minimizing manufacturing expense. The downwardly extending extension 46, with the weapon assembled, will ride on frame shelf 22 and will function as a stop to limit rearward motion of the slide by cooperating with a stop surface 48 which is integral with the frame. The slide subassembly 14 will have, internally thereof, precision machined lands and grooves which cooperate with guide grooves 26 and their associated lands on the frame. The bottom surfaces of slide 14 will also cooperate with the surfaces 52 of the frame to insure alignment of the frame and slide. The forward end of the barrel will be received in and supported by the precision drilled aperture 54 at the forward end of the slide subassem bly 14. The extension 46 of the slide subassembly 14 is also provided with an aperture 56; aperture 56 having a counter bore; the junction between the two portions of aperture 56 providing a shoulder against which the forward end of spring 28 is seated. The guide rod 30 for spring 28 will pass through the smaller diameter portion of aperture 56 and may, if desired, be provided with an easily removable cap or plug ofincreased diameter.

Considering further the slide subassembly 14, it is to be noted that the slide is provided with an arcuate cutout, indicated generally at 58, adjacent its rearward disposed end. Cutout 58 is commensurate in size, for the purposes to be explained below, with the locking piece 18. The slide 14 is also provided with a generally L-shaped groove 60 which communicates with the top rear end of the slide. Groove 60 receives, for the purposes to be described below also, a locking portion of pin 20.

The bolt subassembly 16 will provide the housing for the firing pin, not shown, and the cartridge ejector 62. With the weapon in the assembled condition, the bolt subassembly 16 is, in the manner to be described below, joined to the slide subassembly 14 and moves therewith. The bolt 16 of the preferred embodiment of the present invention is characterized by a recess 64 machined in its upper surface. Recess 64, with the weapon in the assembled condition, will be aligned with cutout 58 in slide 14 and the width of recess 54 and cutout 58 will be substantially equal to the width of locking piece 18. The bolt 16 is also provided with a slot 66 which communicates with the rear top surface of the bolt and extends forward of recess 64. The bolt is further provided with a pair of rearwardly extending arms 68 which provide clearance for hammer 34. It is particularly to be observed that, like the barrel, the bolt may be precisely machined at relatively low cost by means of an inexpensive and inherently accurate turning operation.

It may be noted that the locking piece 18 also defines the rear sight 70 of the weapon. The rear sight could, however, be formed on the top surface of slide 14 or affixed thereto in the same manner as the front sight 72. Locking piece 18 is also provided with a bore 74 which is commensurate in size and shape with the major portion of pin 20. The length of bore 74 will be longer than its diameter with a 5:1 ratio having been employed in one operative embodiment. Also, if desired, the locking piece 18 can be utilized to retain the firing pin in the bolt.

The pin 20 is formed from spring steel. Preferably, but not necessarily, the end of the spring which is bent up and over to define a locking member commensurate in size and shape with groove 60 in the top of slide 14 will be flattened as shown. The locking portion of pin 20 includes an L-shaped tab member 76 which is spring loaded toward the major portion of the pin whereby it will snap into and be self-locking in groove 60.

Presuming that the weapon of FIG. 1 has been taken apart for cleaning or other maintenance procedure, the first step in assembly comprises reinsertion of spring 28 and rod 30. Thereafter, the barrel will be positioned on the frame with the bottom of the minor diameter portion 40 resting in bedding recess 24. As noted above, the completely concentric barrel 12 has two diameters, the major diameter 38 being substantially the same as the bolt diameter. The spring collar 36 surrounds a major portion of the minor diameter section 40 of the barrel and rotation of collar 36 is prevented by engagement of the tongue 41 with the cooperating slot in the major diameter portion of the barrel. When assembled in the manner described the

shoulders

42 and 44 defined by the ends of collar 36 abut against the top of the frame thereby preventing the barrel from turning and keeping the extractor slot, not shown aligned with the extractor 62 on the bolt.

With the barrel held in position, the slide subassembly 14 is inserted from the forward or muzzle end whereby the front end of major diameter portion 38 of barrel 12 will be inserted in aperture 54 and the end of pin will pass through aperture 56. In order to facilitate assembly, the slide may be manually urged toward the rear, thus compressing spring 28, and will be held in the full rearward position by the safety mechanism, not shown, which is mounted on the left side of the frame and in operative relationship to a eutout in the bottom left side of slide 14. Next, the bolt subassembly 16 will be inserted into slide 14 from the rear and will bemoved forwardly until the recess 64 is in alignment with the slide cutout 58. The locking piece 18 will then be dropped into position from the top. Finally, the pin 20 will be inserted from the rear into the slot 66 in the top of the bolt 16; the pin passing through the bore 74 in locking member 18. The pin will be urged forwardly whereby the locking portion 76 thereof will pass up and over the top of slide 14 and snap down into the L.-shaped locking groove 60. Assembly of the weapon will thereupon be completed. Disassembly will, of course, proceed in the opposite sequence with the locking portion 76 of pin 20 being raised out of engagement with groove 611 and removed to the rear as the first step.

In operation, the forces generated by detonation of a cartridge in the chamber of barrel 12 will result, in a manner well known in the art, in the slide and bolt being driven rearwardly until the slide member portion 46 contacts frame stop 48. As the bolt moves rearwardly the extractor 62 will remove the spent cartridge case from the chamber and the cartridge case will be ejected through the ejection port 80 provided therefor in the side of the slide 14. During rearward movement, the slide pushes against the front of lock piece 13 and motion of the slide is thus transmitted to the bolt via the locking piece. It is to be noted that the locking piece 18 will be formed of the quality steel, such as SAE 4140 or equivalent, and will preferably be heat treated as to be able to withstand the forces imparted thereto. It may' also be noted that the lock piece 18 has no sharp corners, which are stress raisers, and has ideal grain flow.

On the closing stroke, the drive spring 28 urges the slide 14 forwardly as far as it will go. During forward motion, the slide pushes against the rear area of lock piece 18 and the lock piece in turn pushes the bolt against the breach face. When the bolt stops against the breach face of the barrel the force of the drive spring will push the slide against the lock piece and it in turn against the bolt closing the gap completely. During forward motion the bolt will, of course, carry a new cartridge from the magazine into the chamber.

To review several of the attributes of the invention, it may be noted that all the forces generated during detonation and subsequent rearward motion of the slide and bolt and also during forward motion of the slide and bolt under influence of the drive spring act upon the lock piece 18. Thus, there are no forces on the locking pin 20. It is also to be noted that the lock piece 18 may be formed so as to blend perfectly with the slide outer configuration without any external projections or indentations. The lock piece can not tilt or tip since, as noted above, the lock pin aperture is longer than its diameter thereby enabling the lock pin to guide the lock piece with a long bearing surface in relation to its diameter.

The caliber of weapons employing the present invention may be changed merely by replacing the magazine, the bolt and barrel. This permits the same frame and slide to be used and enables the weapon to fire inexpensive ammunition while retaining the weight and feel associated with the service or regular caliber weapon.

While a preferred embodiment has been shown and described, various modifications and substitutions may be made to the present invention without departing from the spirit and scope thereof. Thus, while the weapon shown in FIG. 1 employs a cylindrical slide, any shape slide member may be chosen and a lock piece formed to fit the member. Also, while the invention has been shown in the environment of a blow back type weapon, it is suitable for use in many types of weapons including those of the locked breach self loading, submachine, semi and fully automatic rifle and cartridge cannon types. The invention also has utility outside of the firearms art and is particularly well suited for use where a solid and hollow shaft rotate in concert inside a guide tube and must partly leave the guide tubesuch as, for example, in earth boring equipment. Accordingly, it is to be noted that the present invention has been described by way of illustration and not limitation.

What is claimed is:

1. A firearm comprising:

frame means;

barrel means, said barrel means including a barrel having a chamber at one end thereof, said barrel means supported by said frame means at least adjacent a first end of said barrel means;

a slide member mounted for reciprocating motion on said frame means relative to said barrel means, said slide member defining a channel, said slide member further being provided with a cut out which extends generally transversely of the axis of said barrel and which provides communication between the exterior of said slide member and said channel;

bolt means mounted for reciprocating motion relative to said chamber, at least part of said bolt means being commensurate in size and shape with said slide member channel whereby said bolt means is received in said slide member, said bolt means further being provided with a recess in its external surface, said recess being aligned with said slide member cut out and being substantially equal in width to the width of said slide member cut out and having a maximum length substantially equal to said slide member cut out maximum length, said bolt means further having a slot in its exterior surface, said slot extending inwardly from the rearwardly facing end of said bolt means and extending on both sides of said recess;

a locking member having a size and shape at least commensurate with the size and shape of the opening defined by said slide member cut out and bolt means recess, said locking member being positioned in said recess and cut out whereby motion of said slide member is transmitted to said bolt means by said locking member, said locking member being further characterized by an aperture therethrough which is aligned with said bolt means slot; and

locking pin means received in said bolt means slot, said locking pin passing through said locking member aperture.

2. The apparatus of claim 1 wherein said slide member is further characterized by a locking groove in its external surface, at least a portion of said locking groove extending generally transversely of said barrel axis, and wherein said locking pin means comprises:

an elongated portion having a size and shape commensurate with the combined dimensions of said bolt means groove and locking member aperture;

a spring loaded locking portion extending from one end of said elongated portion, said locking portion being partly commensurate in size and shape with said slide member locking groove whereby said locking portion of said pin may be snapped into position in said locking groove.

3. The apparatus of claim 2 wherein said pin means locking portion comprises:

an extension of said pin means elongated portion,

said extension being bent over so as to form a portion oriented generally parallel to said elongated portion, said bent over portion also having a tab extending generally transversely of said barrel axis.

4. The apparatus of claim 1 wherein said frame means further comprises:

drive spring means, said spring means engaging a portion of said slide member for urging said slide member to a forward position; and a precision machined barrel bedding recess for supporting said barrel means adjacent a first end of said barrel.

5. The apparatus of claim 4 wherein said barrel means comprises:

a barrel, said barrel having a first cylindrical portion with a first diameter and a second cylindrical portion located intermediate the ends of said first portion, the diameter of said second portion being less than that of said first portion, the length of said second portion being commensurate with the width of said frame means barrel bedding recess; and

a collar mounted on said barrel and partly circumscribing said second portion thereof, the arc of said second portion of said barrel not circumscribed by said collar cooperating with said barrel bedding recess to provide precision mounting of said barrel, the oppositely disposed ends of said collar cooperating with said frame means to either side of said barrel bedding recess to prevent turning of said barrel.

6. The apparatus of claim 3 wherein said frame means further comprises:

7. The apparatus of claim 6 wherein said barrel means comprises:

8. A firearm comprising:

frame means, said frame means being provided with a precision machined arcuate barrel bedding recess;

a barrel, said barrel being generally of cylindrical shape and having a portion of reduced outer diameter located intermediate its ends, said portion of reduced diameter having a width commensurate with the width of said frame means barrel bedding recess;

a spring loaded barrel collar circumscribing said reduced diameter portion of said barrel, the opposite ends of said collar cooperating with said frame means to prevent rotation of said barrel and the exposed surface of said reduced diameter portion disposed between said collar ends operating with said frame means barrel bedding recess to precisely align said barrel relative to said frame;

slide means mounted for reciprocating motion on said frame means relative to said barrel;

bolt means mounted for reciprocatingmotion with said slide means; and

means for securing said bolt means to said slide means.

9. The apparatus of claim 8 wherein said slide means comprises:

a slide member which defines a channel, said channel partly circumscribing said barrel, said slide member being provided with a cut out which extends generally transversely of the axis of said barrel.

10. The apparatus of claim 9 wherein said bolt means comprises:

a bolt member commensurate in size and shape with said slide member channel whereby said bolt member is received in said channel, said bolt member being provided with a recess in its external surface and aligned with said slide member cut out, said bolt member also having an external slot extending from its rearwardly facing end to a point forwardly of said recess.

11. The apparatus of claim 10 wherein said securing means comprises:

a locking member positioned in said bolt member recess, said locking member being sufficiently larger than said recess so as to contact edges of slide member cut out during motion thereof whereby motion of said slide member is transmitted to said bolt member by said locking member, said locking member further having an aperture therethrough, said aperture being aligned with said bolt member external slot; and

a locking pin received in said bolt member external slot and passing through said locking member aperture.

12. The apparatus of claim 11 wherein said slide member is further characterized by a locking groove in its external surface, at least a portion of said locking groove extending generally transversely of said barrel axis, and wherein said locking pin comprises:

an elongated portion having a size and shape commensurate with the combined dimensions of said bolt member groove and locking member aperture;

aspring loaded locking portion extending from one end of said elongated portion, said locking portion being partly commensurate in size and shape with said slide member locking groove whereby said locking portion of said pin may be snapped into position in said locking groove.

13. The apparatus of claim 12 wherein said pin locking portion comprises:

an extension of said pin elongated portion, said extension being bent over so as to form a portion oriented generally parallel to said elongated portion, said bent over portion also having a tab extending generally transversely of said barrel axis.

Claims

1. A firearm comprising: frame means; barrel means, said barrel means including a barrel having a chamber at one end thereof, said barrel means supported by said frame means at least adjacent a first end of said barrel means; a slide member mounted for reciprocating motion on said frame means relative to said barrel means, said slide member defining a channel, said slide member further being provided with a cut out which extends generally transversely of the axis of said barrel and which provides communication between the exterior of said slide member and said channel; bolt means mounted for reciprocating motion relative to said chamber, at least part of said bolt means being commensurate in size and shape with said slide member channel whereby said bolt means is received in said slide member, said bolt means further being provided with a recess in its external surface, said recess being aligned with said slide member cut out and being substantially equal in width to the width of said slide member cut out and having a maximum length substantially equal to said slide member cut out maximum length, said bolt means further having a slot in its exterior surface, said slot extending inwardly from the rearwardly facing end of said bolt means and extending on both sides of said recess; a locking member having a size and shape at least commensurate with the size and shape of the opening defined by said slide member cut out and bolt means recess, said locking member being positioned in said recess and cut out whereby motion of said slide member is transmitted to said bolt means by said locking member, said locking member being further characterized by an aperture therethrough which is aligned with said bolt means slot; and locking pin means received in said bolt means slot, said locking pin passing through said locking member aperture.

2. The apparatus of claim 1 wherein said slide member is further characterized by a locking groove in its external surface, at least a portion of said locking groove extending generally transversely of said barrel axis, and wherein said locking pin means comprises: an elongated portion having a size and shape commensurate with the combined dimensions of said bolt means groove and locking member aperture; a spring loaded locking portion extending from one end of said elongated portion, said locking portion being partly commensurate in size and shape with Said slide member locking groove whereby said locking portion of said pin may be snapped into position in said locking groove.

3. The apparatus of claim 2 wherein said pin means locking portion comprises: an extension of said pin means elongated portion, said extension being bent over so as to form a portion oriented generally parallel to said elongated portion, said bent over portion also having a tab extending generally transversely of said barrel axis.

4. The apparatus of claim 1 wherein said frame means further comprises: drive spring means, said spring means engaging a portion of said slide member for urging said slide member to a forward position; and a precision machined barrel bedding recess for supporting said barrel means adjacent a first end of said barrel.

5. The apparatus of claim 4 wherein said barrel means comprises: a barrel, said barrel having a first cylindrical portion with a first diameter and a second cylindrical portion located intermediate the ends of said first portion, the diameter of said second portion being less than that of said first portion, the length of said second portion being commensurate with the width of said frame means barrel bedding recess; and a collar mounted on said barrel and partly circumscribing said second portion thereof, the arc of said second portion of said barrel not circumscribed by said collar cooperating with said barrel bedding recess to provide precision mounting of said barrel, the oppositely disposed ends of said collar cooperating with said frame means to either side of said barrel bedding recess to prevent turning of said barrel.

6. The apparatus of claim 3 wherein said frame means further comprises: drive spring means, said spring means engaging a portion of said slide member for urging said slide member to a forward position; and a precision machined barrel bedding recess for supporting said barrel means adjacent a first end of said barrel.

7. The apparatus of claim 6 wherein said barrel means comprises: a barrel, said barrel having a first cylindrical portion with a first diameter and a second cylindrical portion located intermediate the ends of said first portion, the diameter of said second portion being less than that of said first portion, the length of said second portion being commensurate with the width of said frame means barrel bedding recess; and a collar mounted on said barrel and partly circumscribing said second portion thereof, the arc of said second portion of said barrel not circumscribed by said collar cooperating with said barrel bedding recess to provide precision mounting of said barrel, the oppositely disposed ends of said collar cooperating with said frame means to either side of said barrel bedding recess to prevent turning of said barrel.

8. A firearm comprising: frame means, said frame means being provided with a precision machined arcuate barrel bedding recess; a barrel, said barrel being generally of cylindrical shape and having a portion of reduced outer diameter located intermediate its ends, said portion of reduced diameter having a width commensurate with the width of said frame means barrel bedding recess; a spring loaded barrel collar circumscribing said reduced diameter portion of said barrel, the opposite ends of said collar cooperating with said frame means to prevent rotation of said barrel and the exposed surface of said reduced diameter portion disposed between said collar ends operating with said frame means barrel bedding recess to precisely align said barrel relative to said frame; slide means mounted for reciprocating motion on said frame means relative to said barrel; bolt means mounted for reciprocating motion with said slide means; and means for securing said bolt means to said slide means.

9. The apparatus of claim 8 wherein said slide means comprises: a slide member which defines a channel, said channel partly circumscribing said barrel, said slide member being proVided with a cut out which extends generally transversely of the axis of said barrel.

10. The apparatus of claim 9 wherein said bolt means comprises: a bolt member commensurate in size and shape with said slide member channel whereby said bolt member is received in said channel, said bolt member being provided with a recess in its external surface and aligned with said slide member cut out, said bolt member also having an external slot extending from its rearwardly facing end to a point forwardly of said recess.

11. The apparatus of claim 10 wherein said securing means comprises: a locking member positioned in said bolt member recess, said locking member being sufficiently larger than said recess so as to contact edges of said slide member cut out during motion thereof whereby motion of said slide member is transmitted to said bolt member by said locking member, said locking member further having an aperture therethrough, said aperture being aligned with said bolt member external slot; and a locking pin received in said bolt member external slot and passing through said locking member aperture.

12. The apparatus of claim 11 wherein said slide member is further characterized by a locking groove in its external surface, at least a portion of said locking groove extending generally transversely of said barrel axis, and wherein said locking pin comprises: an elongated portion having a size and shape commensurate with the combined dimensions of said bolt member groove and locking member aperture; a spring loaded locking portion extending from one end of said elongated portion, said locking portion being partly commensurate in size and shape with said slide member locking groove whereby said locking portion of said pin may be snapped into position in said locking groove.

13. The apparatus of claim 12 wherein said pin locking portion comprises: an extension of said pin elongated portion, said extension being bent over so as to form a portion oriented generally parallel to said elongated portion, said bent over portion also having a tab extending generally transversely of said barrel axis.