Sept-5,1967 ' o. M. KNODE, JR, ETAL " 3,339,304

SHOTGUN GAUGE ADAPTER ' ’ Filed Oct. 23, 1965' 2 Sheets-Sheet 2

INVENTORS OLIVER M. KNOD£ JR. H ‘ £DWARD M. 5742K ' BY €I § United States Patent 0 1 3,339,304 cc Patented Sept. 5, 1967 1 2 3,339,304 member 14 of the adapter tube 6 is provided GAUGE ADAPTER with a ?ange 18 disposed at one end, as shown in FIGS. Oliver M. Knode, Jr., Hampden, and Edward M. Stark, 1, 5 and 7. The forward face of the ?ange is beveled, East Longmeadow, Mass., assignor to Emhart Corpora as shown at 20 in‘ FIG. 2, to mate with the bevel 22 in tion, Bloom?eld, Conn., a corporation of Connecticut the breech end of the of any standard break Filed Oct. 23, 1965, Ser. No. 503,211 acti'on type shotgun. Thus when the tube is pushed fully 1 Claim. (Cl. 42-77) into the gun barrel, the beveled ?ange centers the chamber This invention relates to gun bore adapters, and more member end of the tube within the barrel. particularly to improved adapter tubes removably inserta The ?ange 18 extends around only a portion of the ble in the gun to reduce the gun bore diameter, thus 10 tube leaving a circumferential notch or slot 24, as seen enabling the same gun to ?re ammunition of gauge or in FIGS. 1 and 7. The slot permits free back and forth caliber smaller than the barrel itself. movement of the shotgun extractor 12, and extends The principal object of this invention is to provide an through a su?iciently large arc to accommodate the widest improved gun-bore adapter, having particular utility in extractors found on standard model . shotguns, of minimum weight capable of use with various 15 In addition to the ?ange or header 18, means for cen types of shotguns without sacri?ce of structural strength tering the adapter tube is also provided at the opposite and safety in the critical breech pressure zone. For ex or muzzle end of the adapter and comprises a ?exible ample, :by use of this adapter any standard 12 gauge shot elastic ring 26, as shown in FIGS. 2 and 5. The ring is gun can be adapted to ?re a .410 gauge or other shell located adjacent the outer end of the barrel piece 16 and of less than 12 gauge by simply inserting a tube in the 20 is ?tted in an annular slot 28 provided in the barrel piece breech end of the barrel. When it is desired to ?re 12 16. The ring may be made of any suitably ?exible, elastic gauge shells, the tube can be readily removed. Moreover, material, such as various synthetic plastics, and including the constructional characteristics of the tube are such that Te?on, neoprene, rubber and the like. The outer diameter insertion and removal is accomplished without injury to of the ring is made su?‘iciently large to provide a snug ?t the barrel. 25 in the gun barrel so that when the adapter is inserted The above and other objects and advantages of this into the barrel, the ring holds it centered and prevents the invention will be more readily perceived from the fol gun barrel being scratched by the metal tube. In addition, lowing description with reference to the accompanying the ‘ring 26 is made of a heat resistant material and is drawings, in which: su?iciently tight to form a gas seal which prevents rear 30 FIG. 1 is a partial perspective view showing an adapter ward escape of the gases. Moreover, the ring is readily removable and replaceable should it become worn or darn tube embodying this invention being inserted into a shot aged in any way. gun barrel; FIG. 2 is an elevational view partly in section showing The con?guration of the chamber, forward of the ?ange or header 18', is in the form of two cylindrical an adapter tube disposed within the barrel of a gun; 35 FIGS. 3 and 4 are bottom partial views showing parts portions 30 and 32 separated by a shoulder 33. (See of the adapter in different operative relationships; FIGS. 1, 2, 3 and- 4.) It will ‘be seen that the ?rst cylin FIG. 5 is a perspective view of the adapter with a sec drical portion has a slightly smaller outer diameter than tion broken away; the barrel so as to provide clearance between the gun FIG. 6 is a sectional view generally taken along line barrel and the adapter tube. Forward of the section 32, 6-6 of FIG. 5; the cartridge member is provided with a circumferentially FIG. 7 is an end view of the breech end of the adapter; extending recess or slot 34 into which is ?tted a clip or and - ring 36 which serves as a stroke limiting and retaining FIGS. 8 and 9 are enlarged perspective views showing means for an extractor member 38 slidably mounted in separately elements of the adapter. longitudinally extending recess 40 provided in the cartridge chamber 14 (FIGS. 2 and 5). 1 Referring now in detail to the drawings, a shotgun 45 7 Forward of the slot 34, the adapter tube continues as a gauge wadapter embodying this invention is shown generally cylindrical section for a su?‘icient distance to provide the at 6 in FIG. 1. The adapter is in the form of a tube re movably insertable into the barrel 8 of any standard break chamber at least as long as a shotgun shell, shown at 42 type of shotgun, shown generally at 10. The shot in FIG. 2. The cartridge chamber 14 then tapers inwardly gun shown is a break-action type and includes an extractor 50 as shown at 45, and terminates in a threaded extension 44 12 operated to extract expended shells from the barrel which screws into a correspondingly threaded bore of the when the action is broken. ‘ barrel piece 16 of the adapter (FIG. 5). The two sections may be permanently locked or bonded in place by the In accordance with this invention, the adapter 6 com addition to the threaded portion 44 of a small amount of prises a cartridge chamber or chamber member 14 with 55 resin adhesive or other suitable material. a barrel piece 16 extending from the front end of the From the threaded coupling, the barrel piece tapers chamber member 14. In the embodiment shown, the inwardly to a cylindrical portion over the major portion chamber member and barrel piece are each separately of its length, as shown at 48 in FIGS. 2 and 5. At its outer formed and joined together in any suitable manner, such end, the tube’s outer diameter increases again to provide as by screw threads provided on the mating ends of the 60 sufficient thickness of metal for ?aring of the inner bore two elements. The separate cartridge chamber 14- and the and for the ring-retaining slot 28, and to provide su?icient barrel piece 16 are each fabricated of a material best diameter so that the elastic ring ?ts snugly into the bar suited for the desired performance characteristics com rel of the shotgun with which it is intend to be used. The mensurate with their respective functions. Preferably to ?are or taper of the inner bore at the terminal end thereof, obtain maximum strength the cartridge chamber member 65 as shown at 50 in FIG. 2, prevents appreciable buildup 14 is made of suitable ferrous metal such as steel having of burned powder residue beyond the muzzle end of the the capability of withstanding peak explosive pressures tube. during ?ring. The barrel, on the other hand, is prefer The extractor bar 38‘, comprises a metal bar, slidably ably made of a lightweight non-ferrous material selected mounted in an undercut open ended longitudinally extend for machineability and strength, such as tempered alumi 70 ing recess 40. In the preferred embodiment of the inven num, magnesium or the like. tion, as seen most clearly in FIGS. 6 and 7, the undercut recess 40 is of dovetail con?guration. In FIG. 9, it will be 8,339,804 3 4 noted that one end of the extractor member is provided erable to lightly oil the resilent ring 26 at the muzzle with radially extending lugs 52 and 54 respectively. The end of the adapter. Then with the clip 36 disposed in ac extractor member is further characterized by a neck por cordance with the length of the extractor stroke of the tion 56 of reduced width which provides oppositely dis particular gun, the adapter is simply pushed into the posed longitudinally extending notches 58 and 60. As will breech end of the shotgun barrel 8 as though it were a be described below, these notches cooperate with the shotgun shell. ‘In doing this the extractor bar 38 is regis spring metal clip 36 to provide adjustable stop means for tered or centered on the extractor 12 of the gun. The adapter is pushed all the way into the barrel so that it is varying the stroke of the extractor bar. The clip 36 (FIGS. 5 and 8) is generally a split ring ?ush with the breech end thereof. The gun can now be loaded and operated, using a smaller gauge shell in exact construction which enables the clip to be ?exed for in ly the same manner as in using larger gauge ammunition. stallation and removal from the slot 34. The free ends of the clip are notched to provide circumferentially ex By providing a cartridge member of steel and light weight barrel piece, such as aluminum, it is possible to tending oppositely disposed projections or tabs 64. These achieve weight reduction of as much as ?fty percent, as tabs extend inwardly of the side edges of recess 40 so as compared with an integral all steel adapter tube. More tointerengagethe extractor member 38 in its outermost 15 position, as shown in FIGS. 3 and 4 of the drawings. over, this drastic weight reduction, most important in hand carried ?rearms, is obtained without sacri?ce in structural Thus, the tabs serve as a stop and retaining means for the strength and safety, since the adapter with its steel cham extractor bar 38. ber member is structurally capable of withstanding peak When the shotgun barrel is opened and the extractor 12 20 explosive pressures and is fabricated with su?icient wall (FIG. 1) moves rearwardly, the gun extractor 12 engages strength whereby the extractor slide and retaining ring the inwardly extending lug 54 of the extractor bar 38 recesses ‘may be cut in the adapter wall without reducing carrying the bar rearwardly until the front, inner shoulders the wall strength below normal safety limits. of notches 58 and 60 come into contact with the projec Having thus described this invention, what is claimed tions 64 of the clip 36 (FIGS. 1 and 2). As clearly shown 25 is: in FIG. 2, the outwardly extending lug 52 of the extractor Adapter to reduce a gun bore diameter comprising a member 38 engages the of the shotgun shell 42 and composite tubular structure having a steel chamber mem extracts it from the chamber member 14 of the adapter ber and a lightweight non-ferrous metal barrel piece tube. When a round is loaded and the action closed, the af?xed to the end of the chamber member, said chamber face 70 (FIG. 1) of the shotgun breech engages in succes 30 member being formed with a longitudinally extending sion, the extractor 12, the extractor bar 38, and the shot undercut recess, an extractor bar slidably mounted in bun shell 42 moving them forwardly. said recess, an elastic ring carried adjacent the terminal As shown in FIG. 4, the clip 36 may be positioned with end of said barrel piece, and a metal clip in the form of a its stop tabs or projections 64 disposed toward the cham split ring disposed on said chamber member, the free ends ber member end of the adapter tube for shotguns having a 35 of said ring terminating in spaced opposed relationship, a long extractor stroke. The clip may be reversed simply by projection extending into the split formed by the free ends snapping it o? the tube and re?tting it thereon with the of said ring, said projection being axially offset from the stop tab 64 disposed toward the muzzle end of the adapter, circumferential center line of said ring so that end-to-end as shown in FIG. 3. In this position of the clip 36, the adapter may be used with shotguns having a short extrac Iraeversal of the clip changes the stroke of said extractor 40 ar. tor stroke. In both positions, the projections cooperate References Cited with the notches in the bar 38 to serve as stop means when contacted by inner edges of the notches. The reversible UNITED STATES PATENTS feature assures that the extractor stroke of the bar 38 252,241 1/1882 Morris ______42—77 will be generally the same length as long or short extrac 45 611,062 9/1898 Darms ______42—77 tor strokes of standard types of shotguns. To achieve this 1,528,561 5/1925 Koller ______42—77 X purpose, the dimension a (FIG. 8) of the clip 36 is made 2,850,828 9/ 1958 Sullivan ______42—76 equal to the difference in length between the long and 3,138,889 6/1964 Groover ______42—77 short extractor strokes of standard break-action type shot 3,156,995 11/1964 Mellor et al. ______42—77 guns. To use the adapter embodying this invention, it is pref BENJAMIN A. BORCHELT, Primary Examiner.