USOO8695260B2
(12) United States Patent (10) Patent No.: US 8,695.260 B2 Kramer (45) Date of Patent: Apr. 15, 2014
(54) CARTRIDGES AND MODIFICATIONS FOR 3,898.933 A 8, 1975 Castera et al. M16/AR15 RFLE 4,057,003 A * 1 1/1977 Atchisson ...... 89,138 4,440,062 A * 4, 1984 McQueen ...... 89/128 5,033,386 A 7/1991 Vatsvog (76) Inventor: Lawrence S. Kramer, Mount 5,351,598 A * 10/1994 Schuetz ...... 89.185 Charleston, NV (US) 5,463,959 A 1 1/1995 Kramer 5.499,569 A 3, 1996 Schuetz (*) Notice: Subject to any disclaimer, the term of this 5,520,019 A 5/1996 Schuetz patent is extended or adjusted under 35 5,987,797 A 1 1/1999 Dustin U.S.C. 154(b) by 120 days 6,293,203 B1 9/2001 Alexander et al. M YW- y yS. 6,609,319 B1 8/2003 Olson 21) Appl. N 12A867,366 6,625,916 B1* 9/2003 Dionne ...... 42/16 (21) Appl. No.: 9 (Continued) (22) PCT Filed: Feb. 13, 2009 OTHER PUBLICATIONS (86). PCT No.: PCT/US2O09/034096 Chastain, R. “Hornady's New Ammo Loadings for 2007. A Mixture S371 (c)(1), of New and Old Cartridges' about.com: hunting and shooting Apr. 5, (2), (4) Date: Aug. 12, 2010 2007 online, retrieved on Oct. 14, 2009. Retrieved from the Internet
EECTOR US 8,695.260 B2 Page 2
(56) References Cited JGS, Rimless or Rebated Rifle Minimum Chamber, SAAMI 223 REM (5.56MM), Print #0517, May 8, 2002. U.S. PATENT DOCUMENTS Johnston, Gary Paul “The 6.8mm Remington SPC.” Internet article dated Apr. 18, 2004, XP-002548838,
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LoweR RECEIVER, PISTOL GRP, auTTSTock, y ArMAGAZINE COPONENTSN His SASSEMBLY US 8,695,260 B2 1. 2 CARTRIDGES AND MODIFICATIONS FOR with the 223 Remington not providing enough performance M16/AR15 RFLE or power and the 308 Winchester providing too much or excessive power. This application is a national stage of International Appli United States Military Needs cation No. PCT/US09/34096, filed Feb. 13, 2009, which 5 The existing standard cartridge or chambering for the mili claims priority to the U.S. Provisional No. 61/028,588, filed tary's M16 rifle is the .223 Remington or 5.56 mm NATO Feb. 14, 2008. (military designation) cartridge. It fires a .224 caliber bullet weighing 62 grains in the military issue M855 ammunition. BACKGROUND OF THE INVENTION Bullets weighing as much as 77 grains are currently in use by 10 the US military to increase the performance of the 5.56 mm 1. Field of the Invention NATO cartridge and have increased the terminal performance Embodiments of the present invention relate generally to of the cartridge, but its terminal effects are still less than cartridges and modifications for an M16/AR15 rifle. desirable for what is considered an adequate combat car 2. Description of the Related Art tridge. The shortcomings in the performance of the 5.56 mm Domestic Law Enforcement Needs 15 NATO cartridge are well documented in current and past Most domestic law enforcement agencies in the United military conflicts, and the cartridge's ineffectiveness is more States utilize the AR15/M16 rifle platform in the course of pronounced when the enemy combatants are under the influ their daily duties, as patrol officers out on the street; it is often ence of drugs that affect the central nervous system. referred to as a “patrol carbine” and is carried by individual An alternative for heavier machine guns is the .308 or 7.62 officers. These rifles are also used by SWAT teams for room mm caliber bullet. The most common military caliber utiliz entry or close quarter's battle (CQB) for close in shooting, ing the .308 or 7.62mm caliber bullet is the 308Winchesteror and are used by some departments as short range Sniper rifles. 7.62 mm NATO cartridge. The performance of the 7.62 The reasons for the selection of this rifle platform are that they NATO is also well documented in combat and is known for its are readily available in many configurations and are fairly increased stopping power. The U.S. M14 rifle fires the 7.62 reasonably priced to Law Enforcement agencies, the AR15's 25 mm NATO cartridge as does the U.S. M240 machinegun, as weight and size are also attractive features of the AR15 as they well as several aircraft mounted machineguns and the mini are easily operable by large men and Smaller stature women. gun. The AK47 also utilizes a 7.62 mm bullet. The limiting factor is the cartridge that it fires, the 223 Rem What is needed is a cartridge that will provide improved ington, most commonly using a 55 grain bullet. Domestic law stopping power without over penetrating, and is compatible enforcement is not held to the military restriction of using full 30 with the standard size M16/AR15 rifle platform. metaljacket projectiles and therefore can choose from a wide variety of available bullet styles and designs, which makes the SUMMARY OF THE INVENTION 223 Remington more effective. Even with the proper selection of ammunition, the 223 Embodiments of the present invention relate generally to Remington is still Substandard for most law enforcement 35 cartridges and modifications for an M16/AR15 rifle. In one applications and has a well known reputation for "over pen embodiment, a modified M16/AR15 rifle or carbine includes etration' with its small-fast bullet. This can result in a bolt having a maximum outside diameter greater than that of extremely dangerous situations for patrol officers working in a standard M16/AR15 bolt; and a bolt extractor pivoted to the a built up urban environment. The small weight or mass of the bolt. The bolt and the bolt extractor are operable to: transport bullet makes it less effective and more prone to deflection on 40 a cartridge from a magazine to a barrel, and eject a spent vehicles when engaged by police, especially when engaging cartridge from the barrel. The rifle or carbine further includes thick windshield glass. Although there are a few “alternate’ a barrel extension configured to receive the bolt; a standard cartridges available that will function in the AR15 rifle, they M16/AR15 upper receiver coupled to the barrel extension; a do not offer enough of an improvement over the existing .223 standard M16/AR15 lower receiver coupled to the upper Remington cartridge chambering to justify the cost in Switch 45 receiver. ing over to them, mainly cost and availability of ammunition In another embodiment, a cartridge includes a bullet hav and magazines. Thus the agencies are limited on their choices ing a diameter greater than or equal to 0.224 inch; and a case of cartridge choices if they maintain the AR15/M16 rifle having a case head diametergreater than or equal to 0.45 inch. platform as their weapon of choice. A length of the cartridge is substantially equal to 2.26 inches. The other choice for law enforcement agencies is the larger 50 In another embodiment, a firearm includes a barrel. The and more costly AR15 “style” rifle made by various compa firearm further includes a bolt operable to transport a car nies that fire the .308Winchester cartridge. The .308 Win tridge from a magazine to the barrel and eject the spent chester is a powerful cartridge and offers a substantial cartridge from the barrel. The firearm further includes a improvement over the much smaller .223 Remington cham spring biasing the bolt toward the barrel and a piston system bering. Most police sniper rifles are chambered in the .308 55 in fluid communication with the barrel. The piston system Winchester and are bolt action guns, which do not allow for includes a body and a piston disposed in the body and oper quick follow up shots if needed. able to move the bolt away from the barrel in response to When quick follow up shots are required the larger AR15 firing of the cartridge and force exhaust gas from the body and style rifles are sometimes used, they are heavier and have into the barrel in response to the spring returning the bolt to more recoil than the smaller rifles, but deliver ample fire 60 the barrel. power when needed. These heavier and larger rifles are not the preferred option for SWAT teams for use in room entry and BRIEF DESCRIPTION OF THE DRAWINGS building clearing operations because the power of the 308 Winchester is too much for inside building operations, due to So that the manner in which the above recited features of muzzle blast, recoil, and over penetration. 65 the present invention can be understood in detail, a more These two calibers represent not only the two most popular particular description of the invention, briefly summarized calibers used in law enforcement but are the two extremes, above, may be had by reference to embodiments, some of US 8,695,260 B2 3 4 which are illustrated in the appended drawings. It is to be 264 caliber/6.5 mm—varmint hunting, rifle competition noted, however, that the appended drawings illustrate only 270 caliber/6.8 mm military, law enforcement, hunting typical embodiments of this invention and are therefore not to 308 caliber/7.62 mm military, law enforcement, hunting be considered limiting of its scope, for the invention may 338 caliber/8.6 mm military, law enforcement, hunting admit to other equally effective embodiments. 440 KINETIC military, law enforcement, door & wall FIGS. 1A-1C illustrate cartridges, according to embodi breeching, hunting ments of the present invention. 440 ENTRY (buckshot)—military, law enforcement, door FIG. 2 is an exploded assembly of a bolt, bolt extractor, and & wall breeching, room entry (CQB), hunting. The barrel barrel extension usable with the cartridges of FIGS. 1A-1C. may be smooth bore or rifled for the 440 ENTRY. FIGS. 3A-3E illustrate details of the bolt of FIG. 2. 10 The bullets may have hollow points and may have full FIGS. 4A-4E illustrate details of the bolt extractor of FIG. metal jackets or be semi-jacketed (lead tip). 2. FIGS. 7A-7D illustrate details of a bolt usable with the FIGS. 5A-5D illustrate details of the barrel extension of FIG 2. cartridges of FIGS. 1A-1C and a modified gas piston system FIGS. 6A-6G illustrate details of a magazine usable with 15 (see FIG. 8), according to another embodiment of the present the cartridges of FIGS. 1A-1C. invention. All dimensions are in inches. FIGS. 7A-7D illustrate details of a bolt usable with the FIG. 8 is a cross section of a gas piston system 800, accord cartridges of FIGS. 1A-1C and a modified gas piston system, ing to another embodiment of the present invention. according to another embodiment of the present invention. The use of gas piston systems in weapons to cycle the FIG. 8 is a cross section of a gas piston system, according action is used in weapons such as the Russian AK47 (1947), to another embodiment of the present invention. the U.S M1 Garand (1939) and the U.S. M14 (1957). There FIG. 9 is an exploded assembly of a prior art M16/AR15. areas many as five gas piston systems currently manufactured for the AR15 rifle by various companies. They use a gas piston DETAILED DESCRIPTION OF THE PREFERRED actuated by "tapped gas” from the fired cartridge via a small EMBODIMENT 25 hole or 'gas port in the barrel, the expanding gas forces the piston to move. As such, the gas from a fired cartridge is FIGS. 1A-1C illustrate cartridges, according to embodi utilized to cycle the action and load the next cartridge. The ments of the present invention. expanding gas from the fired cartridge, once utilized to cycle The 308 ERC was designed to maximize the performance the piston, is then vented out of the gas manifold at the end of of the AR15/M16 rifle, give it more stopping or incapacitation 30 the piston operating stroke before the piston returns to the power and increase its performance in self defense, law starting position. enforcement, and military combat applications. The 308 ERC The standard design gas system used in AR15 and M16 is based on the .308Winchester or 7.62 mm NATO cartridge, rifles utilizes a “direct gas impingement system’ which utilizes the 308 caliberbullet, and is designed to operate in the directs expanding gas from the fired cartridge out of the barrel existing standard issue sized AR15/M16 rifle platform. 35 through a “gas port” or hole in the barrel. The expanding Cartridge Details; "tapped gas” is then directed through a “gas tube' which Case head diameter, 0.473" inches (a 25% increase over “directs the gas back into the upper receiver. The gas then the 223 Remington/5.56 NATO) enters the “bolt carrier key” forcing the carrier to the rear and NL is an abbreviation for neck length. NW is an abbrevia unlocking the bolt of the rifle, beginning the cycling process. tion for neck wall. COL is an abbreviation for cartridge over 40 The gas piston system 800 may include a barrel 805, a all length. piston/rod assembly 810, a gas block 815, and a gas block cap Powder capacity: 52% increase over the 223 Remington/ 820. The gas block 815 may have a bore formed therethrough, 5.56 NATO & 18% less than the 308 Winchester may be disposed around the barrel 805, and secured to the Projected design performance data; barrel 805 with fasteners (not shown), such as screws or pins. Bullet weight: 135-140 grains 45 The gas block 815 may have a piston chamber formed therein. Muzzle velocity: 2650 feet per second (fps) (16" barreled A piston 810p of the piston/rod assembly 810 may be dis AR15/M16 carbine) posed in the piston chamber. The piston 810p may divide the Muzzle energy: 2106 foot pounds chamber into an air Sub-chamber and an exhaust Sub-cham Muzzle energy increase: 82% (compared to military cur ber. The piston 810p may be longitudinally coupled to a rod rent issue M855 62 grain FMJBTWC(a 2900 fps fired from a 50 810r of the piston/rod assembly 810, such as by being formed 16" barreled AR15/M16 carbine) integrally therewith or welded thereto. The piston 810p may FIG. 2 is an exploded assembly of a bolt, bolt extractor, and include an array of carbon grooves (not shown) formed barrel extension usable with the cartridges of FIGS. 1A-1C. around an outer surface thereof. The cap 820 may be coupled Although the cartridge is designed to operate in the AR15/ to the gas block 815 by a threaded connection. The rod 810r M16 platform, the following design changes were required 55 may extend through a bore formed through the cap 820. The (in addition to modification of the barrel); cap may have one or more ports 820p formed therethrough 204-ERC redesigned bolt and providing air communication between air Sub-chamber 206-ERC redesigned bolt extractor and the atmosphere. The gas block 815 may have a channel 202-ERC redesigned barrel extension 815c formed between the chamber and the bore and providing FIG. 6A-6G-ERC redesigned magazines, 25 round capac 60 fluid communication between the exhaust sub-chamber and a ity port 805p formed through a wall of the barrel 805. The port Additional ERC cartridges: 805p may provide fluid communication between a bore 805b Although any of these cartridges utilizing the ERC case can of the barrel 805 and the channel 815c. The bore 805b barrel be used for self defense or law enforcement applications, their may be rifled (not shown) to impart rotation to a bullet (not projected use is listed below: 65 shown) fired therethrough. The piston 810p may include a 224 caliber/5.7 mm—varmint hunting, rifle competition recess formed therein in fluid communication with the 243 caliber/6 mm—varmint hunting, rifle competition exhaust sub-chamber. One or more ports 810h may beformed US 8,695,260 B2 5 6 through a wall of the piston 810p and may provide fluid a standard M16/M4 lower receiver (existing M16A1-A4 communication between the channel 815c and the piston versions and M4 and M4A1 versions) coupled to the CSS. upper receiver. In operation, as the bullet passes the gas port 805p in the 2. The rifle or carbine of claim 1, wherein the case head barrel 805, and before the bullet exits the barrel, the exhaust 5 diameter is greater than or equal to 0.4 inch. Sub-chamber becomes pressurized from the expanding gas of 3. The rifle or carbine of claim 2, wherein the bullet diam the fired cartridge via (port 805p, channel 815c, and ports eter is greater than or equal to 6 mm. 810h). The pressurized exhaust gas forces the piston 810p to 4. The rifle or carbine of claim 2, wherein the bullet diam the rear of the piston chamber or “full stroke' position. The eter is greater than or equal to 6.5 mm. operating rod 810rpushes on the bolt carrier key (see FIG.9), 10 which then moves the bolt carrier to the rear, unlocking the 5. The rifle or carbine of claim 2, wherein the bullet diam bolt and cycling the rifles action. As the bolt carrier is forced eter is greater than or equal to 6.8 mm. to the rear, it compresses the rifles main operating spring 6. The rifle or carbine of claim 1, wherein the case head (buffer spring). Air in the air sub-chamber is vented to the diameter is greater than or equal to 0.425 inch. atmosphere via the ports 820p. 15 7. The rifle or carbine of claim 1, wherein the case head Once the bullet has exited the muzzle or flash suppressor diameter is greater than or equal to 0.45 inch. and the pressure in the rifle bore decreases, the piston/rod 8. The rifle or carbine of claim 1, further comprising the assembly 810 is pushed back to the forward or “resting posi magazine configured to hold a plurality of the cartridges. tion” by the expanding buffer spring. As the bolt and bolt 9. The rifle or carbine of claim 1, further comprising the carrier continue forward, the bolt carrier is returned all the barrel configured to receive the cartridge and connected to the way to the forward position, locking the bolt. The residual gas barrel extension. in the piston chamber is exhausted back into the barrel 10. The rifle or carbine of claim 1, wherein the bolt has an through the gas channel 815c and gas port 805p. The firing inside diameter (I in FIG. 3C) greater than that of the standard sequence is now complete, and the rifle is now ready to fire M16/M4 bolt. again. The gas piston system 800 keeps exhaust gas near the 25 11. The rifle or carbine of claim 10, wherein the barrel front end of the gun and in the barrel instead of discharging extension has a maximum inside diameter (I in FIG. 5C) the gas into the upper receiver as the conventional M16/AR15 greater than that of a standard M16/M4 barrel extension (ex gas impingement System does. isting M16A1-A4 versions and M4 and M4A1 versions). Alternatively, the gas piston system may be incorporated 12. The rifle or carbine of claim 11, wherein: into the front sight. Alternatively, the ports 810h may be 30 the bolt has an outer diameter (H in FIG. 3C) greater than omitted and the channel 815c may be in direct fluid commu that of the standard M16/M4 bolt, and nication with the piston recess. Alternatively, the ports 810h the barrel extension has an inner diameter (J in FIG.5C) may be omitted, a primary channel may be in direct fluid greater than that of the standard M16/M4 barrel exten communication with the piston recess and an auxiliary gas S1O. channel may be in fluid communication with the exhaust 35 13. A modified M16 rifle or M4 carbine, comprising: sub-chamber when the piston is in the full stroke position, a bolt having a maximum outside diameter (Kin FIG. 3C) thereby aiding venting of the exhaust gas into the barrel and and an inside diameter (I in FIG. 3C) greater than those accelerating return of the piston to the at-rest position. of a standard M16/M4 bolt (existing M16A1-A4 ver While the foregoing is directed to embodiments of the sions and M4 and M4A1 versions); present invention, other and further embodiments of the 40 an ejector carried by the bolt; invention may be devised without departing from the basic a bolt extractor pivoted to the bolt, scope thereof, and the scope thereof is determined by the wherein: claims that follow. the bolt, the ejector, and the bolt extractor operable to: What is claimed is: transport a cartridge from a magazine to a barrel, and 1. A modified M16 rifle or M4 carbine, comprising: 45 eject a spent cartridge from the barrel, a bolt having a maximum outside diameter (K in FIG. 3C) a length of the cartridge is equal to or slightly less than greater than that of a standard M16/M4 bolt (existing 2.26 inches, and the cartridge comprises: M16A1-A4 versions and M4 and M4A1 versions); a case having a case head diameter greater than 0.378 an ejector carried by the bolt; inch; and a bolt extractor pivoted to the bolt and having a maximum 50 a bullet having a diameter greater than or equal to width (F in FIG. 4D) greater than that of a standard 0.224 inch; M16/M4 bolt extractor (existing M16A1-A4 versions a barrel extension having a maximum inside diameter (I in and M4 and M4A1 versions), FIG.5C) greater than that of a standard M16/M4 barrel wherein: extension (existing M16A1-A4 versions and M4 and the bolt, the ejector, and the bolt extractor operable to: 55 M4A1 versions) for receiving the bolt; transport a cartridge from a magazine to a barrel, and a standard M16/M4 upper receiver (existing M16A1-A4 eject a spent cartridge from the barrel, versions and M4 and M4A1 versions) coupled to the a length of the cartridge is equal to or slightly less than barrel extension; and 2.26 inches, and the cartridge comprises: a standard M16/M4 lower receiver (existing M16A1-A4 a case having a case head diameter greater than 0.378 60 versions and M4 and M4A1 versions) coupled to the inch; and upper receiver. a bullet having a diameter greater than or equal to 14. The rifle or carbine of claim 13, wherein: 0.224 inch; the bolt has an outer diameter (H in FIG. 3C) greater than a barrel extension configured to receive the bolt; that of the standard M16/M4 bolt, and a standard M16/M4 upper receiver (existing M16A1-A4 65 the barrel extension has an inner diameter (J in FIG.5C) versions and M4 and M4A1 versions) coupled to the greater than that of the standard M16/M4 barrel exten barrel extension; and S1O. US 8,695,260 B2 7 15. The rifle or carbine of claim 13, wherein: the case head diameter is greater than or equal to 0.4 inch, and the bullet diameter is greater than or equal to 6 mm. k k k k k