RECENT DEVELOPMENTS IN SHORT PISTON

BATTLE RIFLES

Dolarian Capital Inc (559) 243-0117 (USA Pacific Time Zone)

Email: Dolarian@Dolarian.com Compiled by M. Duenes

Short Piston Battle Rifles

Manufacturer Model Number Caliber Country of

Origin/Manufacture

Magazine Type Notes

LWRC International

SABR 7.62

NATO

USA SR-25 type Not adopted in any numbers

Heckler & Koch

HK416 5.56

NATO

Germany/USA Std M16/M4 magazine,

STANAG Type

-Indonesia - Indonesian Marine Corps Counter Terrorist Unit, Detasemen Jala

Mengkara (Denjaka).

-Netherlands - The Netherlands Army

special forces unit Korps

Commandotroepen

-Norway new standard assault rifle,

-Turkey - replacement for the currently

issued G3 rifle.

-United Kingdom - The HK416 is used by

the British Special Air Service

-United States - It is used by the U.S.

Army's 1st Special Forces Operational

Detachment-Delta,

Heckler & Koch

HK417 7.62

NATO

Germany/USA Proprietary Polymer

magazine

Undergoing testing by USSPECOP

Command

Beretta

ARX-160 5.56

NATO

Italy Std M16/M4 magazine,

STANAG Type

Under development Polymer reciever

FNH

SCAR 17 7.62

NATO

Belgium

USA

Proprietary Polymer

magazine

Adopted in small numbers by US Special Forces

Lewis Machine Tool

LMT

5.56

NATO

USA Std M16/M4 magazine,

STANAG Type

Smith & Wesson M&P-15PS 5.56

NATO

USA Std M16/M4 magazine,

STANAG Type

Patriot Ordnance

Factory

P415 7.62

NATO

USA DPMS, KNIGHT

ARMAMENT, OR the

ORIGINAL AR-10

WAFFLE MAGAZINES

SIG 556 5.56

NATO

Swiss Std M16/M4 magazine,

STANAG Type

Piston VS Gas Operation

Theory of Operation

The current US Battle Rifle, the M16/M4 family, is a gas operated weapon system. In

the M16 family the gas system used is known as a direct impingement system. In this

type of system, as the weapon is fired, gas is bled off from a port located near the end of

the barrel, this gas is directed, via a gas tube, back toward the upper receiver where it

forces the bolt carrier back, unlocking the bolt and forcing the bolt/bolt carrier assembly

to the rear, extracting the fired cartridge case and ejecting it from the upper receiver. The

bolt carrier’s rearward momentum is taken up by the buffer and buffer spring which

forces the bolt carrier forward, stripping a new round from the magazine, seating it into

the chamber, and then locking the bolt to the barrel extension in preparation of firing the

new round.

The AK 47, FN-FAL, SIG 550 family and other battle rifles use the short piston method

of operation. In this type of system as gas is bled off from the barrel port it strikes the

forward portion of a rod which acts as a piston. The force of the gasses causes the piston

/rod to convert the gas pressure to linear kinetic movement. The rod is forced to the rear

where it acts upon the bolt locking mechanism which then initiates the weapons

extraction/loading sequence.

Issues

In the direct impingement system, its very nature involves the movement of hot gasses,

burnt and unburnt powder residue from the muzzle area and venting them in proximity of

the bolt, bolt locking area and the magazine well. This debris can cause function

difficulties if the weapon is not cleaned on a regular basis, which can be difficult to do

especially in a long term combat situation. In long sessions of full automatic fire the hot

gases can cause the chamber area to become so hot the an unfired round can “cook off”,

that is to fire, due to the thermal mass caused by the hot gasses on the metal chamber area

of the weapon.

In the short piston weapon the gasses are vented just outside of the forward mounted vent

block which cuts down on the debris and heat deposited in the chamber/bolt area. One

disadvantage in the piston system is the belief that the action of the gas piston/rod causes

a more violent unlocking of the bolt mechanism.

LWRC International SABR

The unique LWRCI Sniper/Assaulter Battle Rifle (SABR™) is a full spectrum weapon system designed to put devastating 7.62mm NATO rounds on target in a variety of roles. The SABR™ rifle allows a marksman to perform assaulter duty with the 12” barreled upper installed, and quickly switch to a sniper role simply by changing to the 20” barreled upper. The extra upper receiver assembly is carried in a specially designed pack that takes up less room and weighs less than carrying a separate rifle. The SABR™ rifle utilizes our patented self-regulating, short-stroke gas-piston operating system, ensuring unparalleled reliability in the harshest theaters of operation. A side-mounted charging handle allows the shooter to perform reloads without removing their eyes from the target, and prevents any gas blowback to the face when using a suppressor. The ARM-R™ rails are easily removable and reinstalled with a hex key and provide a 100% return to zero for optics and lasers. Each SABR™ rifle comes with one barrel length but extra barreled uppers are available in light contour 12.7”, 16.1”, medium contour 18” and heavy contour 20” configurations. The SABR™ rifle is available in three models: Standard Model (12.7”, 16.1”), Designated Marksman Rifle (18”), and Sniper Model (20”). The DMR and Sniper models will feature Geissele triggers. Custom packages including one lower and two or more barreled uppers are available.

Land Warfare Resources Corporation is a CAGE defense contractor that was founded in 1999. In January of 2006, at the time of

its inception it was known as the Leitner Wise Research Corporation, the company was purchased in a Management Buyout by

Pat Bryan who is the Chairman/CEO of LWRC and an Army Veteran. From inception until reorganization in early 2006, the

company was primarily engaged in R&D activities. With the reorganization the company has moved into full fledged firearms

manufacturing, now located in Springfield Virginia where the corporate headquarters and manufacturing facilities reside. Along

with the management buyout, LWRC absorbed Grenadier Precision Ltd. Co. of Texas. Previously, Grenadier Precision informally

worked with LWRC in the design and manufacturing of the ARM-R (Accessory Rail Modular - Rifle) rail system which was

purpose built for the LWRC short stroke piston operated carbines. Jesse Gomez and Darren Mellors contributed to the design

and engineering evolution of the rifle systems and assisting LWRC with new product development. Jesse Gomez is current the

Vice President of Design and Engineering, and Darren Mellors the Vice-President of Business Development for Land Warfare

Resources Corporation. Our mission at LWRC is to provide absolutely reliable, accurate, durable tools for the warfighter, hunter,

or sportsman through engineering, design and use of the most modern manufacturing and materials technologies. We design

and engineer our products tailored to the end users requirements. We can supply complete weapons, drop on upper halves, or

convert current piston guns to self regulating short stroke piston operation.

H&K 416 Rifle

Caliber: 5.56x45mm NATO Action: Gas operated, rotating bolt Overall length (stock collapsed/extended): 10" barrel: 686 / 785 mm; 14" barrel: Barrel lengths: 10.5" / 267mm; 14.5" / 368mm; 16.5" / 419mm and 20" / 508mm Weight: 3.31 kg w. 10.5" barrel, 3.5kg w 14.5" barrel Rate of fire: 700-900 rounds per minute Magazine capacity: 30 rounds Following the revision of the OICW Block 1 / XM8 program, the Heckler & Koch Company decided to enter the US military and law enforcement markets with the alternative design, which, in fact, looks quite promising. Based on the experience, gained during successful upgrade program of the British SA80 / L85A1 program, HK decided to cure the existing M16 rifles and M4 carbines from most of their problems, inherent to this 40-years old design. The key improvements, made by HK, are their patented short-stroke gas piston system, borrowed from HK G36 rifle. This system replaced the direct gas system of standard M16 rifle, so no powder residue will remain in the receiver even after long shooting sessions. The "new" gas system also is self-regulating and will work reliably with any barrel length. Other improvements include new buffer assembly, improved bolt, and a cold hammer forged barrel, as well as free-floating handguard with integral Picatinny-type rails. Originally developed as a "drop-in" upper receiver assembly for any

standard M16/M4 type lower receiver, HK416 is also available as a complete weapon, with HK-made lower receivers. Current (late 2005) models include carbines with 10.5" and 14.5" barrels, and 16.5" barreled carbine and 20" barreled rifle will be added later. Another interesting development, which is apparently based on the upscaled HK416 design, is the HK417 - the 7.62x51NATO rifle that combines AR-15/M16 type ergonomics, layout and handling with improved reliability of HK-made and designed gas piston system. This rifle probably will use HK G3-type magazines. If the rumors about HK417 are true, the 5.56mm HK416 / 7.62mm HK417 combination will be a direct rival to the newest FN SCAR system. HK416 is a gas operated, selective fired weapon of modular design. It uses short-stroke gas piston that operates the 7-lug rotating bolt. Receiver is made from high grade aluminum alloy. Combination-type safety / fire selector allows for single shots and full automatic mode. Hk416 retains all M16-style controls, including last round bolt hold-open device, rear-based charging handle and magazine release button on the right side of the magazine well. HK416 is fitted with four Picatinny rails as standard, and may accept any type of sighting devices on STANAG-1913 compliant mounts. It also can accept modified HK AG36/AG-C 40mm grenade launcher, which is clamped directly to bottom rail. Buttstock is of typical M4 design, multi-position telescoped.

H&K 417 Rifle

Caliber: 7,62x51mm NATO Action: Gas operated, rotating bolt Overall length: 905 - 985 mm with 406 mm barrel / 35.6" - 38.8" with 16" barrel Barrel length: 305 mm / 12", 406 mm / 16" or 508 mm / 20" Weight: 4.36 kg - 4.96 kg, depending on barrel length Rate of fire: 600 rounds per minute Magazine capacity: 10 or 20 rounds HK417 assault rifle was recently developed by famous German arms-making company Heckler und Koch, as a "big brother" to the 5.56mm HK416 assault rifle. Information on this weapon first surfaced in 2005, on the wave of new interest for the 7.62mm NATO caliber military rifles. This interest came in from experience of international forces gained in Afghanistan and Iraq, where increased range and penetration of the 7.62mm NATO bullets was (and still is) quite useful. Several companies developed new or updated versions of 7.62mm weapons, with intent to sell to military, law enforcement and in certain cases - to civilian shooters as well. The HK417 is one of such weapons. It is primarily oriented toward US market, as it mimics the popular 5.56mm AR-15 / M16 rifles in external appearance, controls, and many design features. However, there are more than few new and original features in HK417, including Heckler-Koch's patented piston-operated gas system, user-changeable barrels etc. Like most other competitors, HK417

rifles are available in several barrel lengths, suitable for full scale of military operations, from close combat in urban or forest areas and up to long-range accurate shooting. HK417 rifle is a gas operated, selective fired weapon of modular design. It uses short-stroke gas piston located above the barrel, that operates the 7-lug rotating bolt. Barrels are cold hammer forged, and could be replaced by end user in several minutes using simple tools. There are four basic patterns of barrels available for HK417 as of now (2008):305 mm / 12" and 406 mm / 16" standard barrels and 406 mm / 16" and 508 mm / 20" accurized barrels. Accurized barrels provide 1 MOA accuracy (with proper ammunition). Receiver is made from high grade aluminum alloy and consists of two parts (upper and lower), connected by two cross-pins a-la AR-15 / M16 rifles. Combination-type safety / fire selector allows for single shots and full automatic mode. HK417 retains all M16-style controls, including last round bolt hold-open device, bolt closure device, rear-based charging handle and magazine release button on the right side of the magazine well. HK417 is fitted with four Picatinny rails on free-float handguard as standard, and will accept any type of sighting devices on STANAG-1913 compliant mounts. It also can accept modified HK AG36/AG-C 40mm grenade launcher, which is clamped directly to bottom rail. Buttstock is of modified M4 design, multi-position telescoped. Production HK417 rifles use proprietary 10- or 20-round box magazines, made of translucent polymer (early prototypes used HK G3 magazines).

Beretta ARX-160

Caliber: 5.56x45mm NATO Action: Gas operated, rotating bolt Overall length: 820-900 mm with 406 mm barrel and butt in ready position; 700 mm with butt folded Barrel length: 305 mm / 12" or 406 mm / 16", quick changeable Weight: ~ 3 kg with 406 mm barrel, w/o magazine Rate of fire: rounds per minute Magazine capacity: 30 rounds

The Beretta ARX-160 assault rifle is, as of mid-2008, still in prototype / development stage. It is a part of the Italian Army's 'Soldato Futuro' program, and is developed by famous Italian company Beretta in close cooperation with army. The rifle is a part of a massive soldier equipment package, which, among other items, will include an advanced rifle sight witch will combine day and night time (optical, TV and IR) view / sight capabilities and laser pointer (also visible and IR). Another component of the Soldato Futuro system is an advanced 40mm single-shot grenade launcher, which will be either installed on the rifle (using Picatinny rail interface) or used as stand-alone weapon (by adding a detachable pistol grip and telescoped stock to it).

The Beretta ARX-160 assault rifle is gas operated weapon that utilizes conventional piston-operated action, with gas piston located above the barrel. Barrel locking is achieved by more or less conventional rotary bolt. Unlike most other assault rifles, the Beretta ARX-160 assault rifle features quick-detachable barrels, which can be changed by operator in the field by depressing the barrel release button (located on right side of receiver, in front of magazine housing), pulling the barrel forward and out of the gun, and then inserting another (or same) barrel back. The receiver consists of two parts, upper (which holds barrel and bolt group) and lower (which hosts magazine housing, trigger unit and pistol grip). Both halves are made from impact-resistant polymer and connected using special quick-release locks, so there are no pins to push out (and lose). Another interesting and unusual feature of the Beretta ARX-160 assault rifle is that it has selectable left / right side ejection system with dual ejection ports (on either side of the gun) and user-switchable left / right position of cocking handle. To change the direction of empty case ejection, user has to push the cross-bolt button, located above and slightly to the rear of pistol grip, by the tip of the bullet (or other pointed item). This affects dual extractor-ejector claws, installed on the bolt, forcing them to eject spent cartridge to the desired side without any further disassembly of the gun or parts change. Charging handle, which is attached to the bolt carrier, also can be installed on either side of the gun. The Beretta ARX-160 assault rifle fires from closed bolt, in single shots and full automatic mode, and has ambidextrous safety / fire mode selector switch conveniently located above pistol grip. Upper receiver is fitted with full-length Picatinny type rail, made of aluminum, which can accommodate a wide variety of sighting equipment, including iron, telescopic, red-dot or electronic sights. Standard open sights are mounted on folding bases using rail interface. Additional lengths of Picatinny rail are installed on the forend on 3-, 6- and 9- o'clock positions. Lower (6-o'clock) position rail is strong enough to host GLX 160 40mm single-shot grenade launcher. Standard buttstock is also made of plastic, and folds to the right side. The buttstock is of telescoped, user-adjustable design.

FNH SCAR 17

Caliber: 7.62X51mm NATO

Action: Gas operated, rotating bolt

Overall length: 997mm (max)/ 770mm (min)

Barrel length: 330 mm/13” (CQC), 406mm/16” (Std), 508mm/20” (LB)

Weight: ~ 3.86 kg w/o magazine

Rate of fire: 600rounds per minute

Magazine capacity: 20 rounds

The US Special Operations Command (US SOCOM) issued a solicitation for the procurement of SOF Combat Assault Rifles (SCAR) on October 15th, 2003. This solicitation requested a new combat rifle, specially tailored for the current and proposed future needs of the US Special Forces, which are somewhat different from latest generic US Army requirements, which are being fulfilled by the newest Heckler-Koch XM8 assault rifle. The key difference in basic requirements between XM8 and SCAR is that, while XM8 is a single-caliber weapon system, tailored for 5.56x45mm NATO ammunition, the SCAR should be available in various different calibers. Initial SOF requirements included two basic versions of SCAR system - the SCAR Light (SCAR-L), available in 5.56mm NATO, and the SCAR heavy (SCAR-H), which should be initially available in significantly more powerful 7.62x51 NATO chambering, and should

be easily adaptable in the field to other chamberings. These other chamberings initially include the well-spread 7.62x39 M43 ammunition of the Soviet / Russian origins, and probably some others (like the proposed 6.8x43 Remington SPC cartridge, especially developed for US Special Forces). The key idea of SCAR rifle system is that it will provide the Special Forces operators with wide variety of options, from short-barreled 5.56mm SCAR-L CQC variation, tailored for urban close combat, and up to long range 7.62x51 SCAR-H Sniper variant, as well as 7.62x39 SCAR-H, which will accept "battlefield pickup" AK-47/AKM magazines with 7.62 M43 ammunition, available during the operations behind the enemy lines. Both SCAR-L and SCAR-H shall be initially available in three versions, Standard (S), Close Quarters Combat (CQC) and Sniper Variant (SV; now it is dubbed Long Barrel - LB). All these variants, regardless the caliber and exact configuration, will provide the operator with the same controls layout, same handling and maintenance procedures, and same optional equipment, such as sights, scopes, and other current and future attachments. Late in 2004 US SOCOM announced, that the winner for the initial SCAR contracts is the FN USA, an US-based subsidiary of the famous Belgian company Fabrique Nationale Herstal. prototype rifles were manufactured by FN Manufacturing Inc, US-based subsidiary to FN Herstal; This company will also handle series production of rifles. Starting mid-2005, first SCAR rifles went to end users in US Special Operation Forces. Since US SOCOM uses Navy-type "mark" designations, SCAR rifles were officially designated as 5.56mm Rifle Mark 16 (SCAR-L / Light) and 7.62mm Rifle Mark 17 (SCAR-H / Heavy). It is believed that Mk.16 and Mk.17 rifles will gradually replace most rifle systems now in service with US SOCOM forces, such as M4 carbines, M16 rifles, M14 rifles and Mk. 25 sniper rifles. As it turned out, FN SCAR rifles are not based on any previous weapons but designed from the scratch. In all variants FN SCAR rifles feature gas operated, short stroke piston action with rotating bolt locking. Bolt system appears to be somewhat similar to that of FN Minimi / M249 SAW machine gun. This system apparently is less sensitive to fine sand, dust and any other fouling inside the receiver, than any system with M16-type multi-lug bolt and plunger-type ejector. Receiver is made from two parts, upper and lower, connected with two cross-pins. Upper part is made from extruded aluminium, lower part is made from polymer. SCAR-L and SCAR-H use similar upper receivers that differ only in the size of ejection port. Other different parts include caliber-specific bolt, barrel, and lower receiver with integral magazine housing. Parts commonality between SCAR-L and SCAR-H is astonishing 90%. Barrels are quick-detachable, and held in the upper receiver with two cross-bolts. Barrel change procedure requires minimum amount of tools, takes just several minutes and there is no need to adjust the headspace after the change. The trigger unit with ambidextrous safety-fire mode selector switch allows for single shots and full automatic fire, with no provisions for limited-length bursts mode. The charging handle could be easily installed on either side of the weapon, so the upper receiver has respective cuts on both sides. Top of the upper receiver is covered by the full-length integral Picatinny rail (MIL-STD 1913); additional Picatinny rails are mounted on both sides and under the free-floating handguards. Side-folding polymer buttstock is adjustable for length of pull, and is shaped to provide positive cheek rest with adjustable cheek support. SCAR rifles are fitted with removable, adjustable iron sights, with folding diopter-type rear sight on the receiver rail, and folding front sight on the gas block. Any additional type of sighting equipment, necessary for current tasks, including telescope and night sights, can be installed using MIL-STD 1913 compatible mounts. Mk.16 SCAR-L rifle will use improved M16-type magazines, made of steel; Mk.17 SCAR-H will use proprietary 20-round magazines

in 7.62x51 NATO chambering, or standard AK-type magazines in proposed 7.62x39 M43 chambering. Current prototypes of SCAR rifles do not have bayonet mounts, and, probably, will never have one.

Lewis Machine Tool CQB MRP Defender Model Piston 16

The CQB MRP Defender Model Piston 16 features a monolithic rail platform upper receiver with 16” chrome lined barrel,

standard trigger group, semi auto bolt carrier group and SOPMOD buttstock assembly.

Smith & Wesson M&P15PS

Model: M&P15

Caliber: 5.56mm Capacity: 30 Round Detachable Magazine

Action: Semi-Auto Barrel Length: 16"

Barrel Twist: 1 in 9" Overall Length: 35" Extended/32" Collapsed

Stock: Collapsible 6-position

Weight: 6.5 lbs. Barrel Material: 4140 Steel

Receiver Material: 7075 T6 Aluminum Finish: Hard Coat Black Anodized

Chromed Comp: Barrel Bore, Gas Key, Bolt Carrier, Chamber

Piston Operating System

Patriot Ordnance Factory (POF)

P415

Information and Specifications:

Barrel: 16.5" Heavy contour, Fluted to reduce weight and heat 4150 Mil-B-1159F Vanadium Alloy (machinegun rated) 70 Rockwell case hardened heat treated "5R" polygonal barrels are 2X

harder then Mil-Spec & Hammer Forged barrels Corrosion resistant and 10 times thicker and hardness than mil-spec

chromed lining "5R" Polygonal Rifled barrels from Rock Creek Barrels, Inc. BC-A5 Muzzle Device Chamber: 7.62X51 mm NATO (.308 Cal.)

Method of Operation: Gas Piston operated, rotating bolt (short stroke system) Reversible piston / gas trap design (two modes of fire) C.R.O.S. (Corrosion Resistant Operating System):

Chrome plated: Barrel, Gas Block/Tube (billet machined), Gas Plug (billet machined), Gas Piston (billet machined), Bolt Carrier Assembly (one piece

Upper Receiver: Modular Railed Receiver (MRR). Billet Machined 7075-T6 aircraft

aluminum alloy A3 Flattop: Nickel Teflon Plated Charging handle: Nickel Teflon Coated

Lower Receiver: P-308, Billet Machined 7075-T6 aircraft aluminum alloy, w/Integral

Oversized Trigger Guard AMBI-BOLT Release Lever Machined Into The Lower Receiver Hard coat anodized per Mil Spec and Teflon coated black Timney MFG. Drop-In 4 Lbs Single Stage Trigger Group ERGO Pistol Grip VLTOR "EMOD" 6 Position Retractable Buttstock w/Mil-spec tube

Handguards: Ergo ladder rail covers

billet machined), Silicone Nickel plated A3 Flattop Upper Receiver and Charging Handle. OUR GAS PISTON WEAPON SYSTEMS REQUIRING NO LUBE! Bolt & Carrier: Chrome plated 8620 Integral Keyed, Steel Bolt Carrier (billet machined),

heat treated / plated per Mil Spec. Chrome plated Bolt, heat treated, to Mil-spec

Sights: Fixed Removable FTA-2005 Hooded, Snag Free Front Site Assemble Troy flip up rear site (optional)

Weight: Empty – 8.75 Lbs

POF-USA: MODULAR RAILED RECEIVER (MRR), Continuous / Monolithic Top Rail, Tactical Rail system Magazines: Uses DPMS, KNIGHT ARMAMENT, OR the ORIGINAL AR-10 WAFFLE

MAGAZINES POF-USA Specifications: All raw materials are manufactured from US Steel Mills. All heat treats, plating/coatings, are completed by U.S.A. owned and

operated manufacturers. All accessory and component parts on our weapons systems are from

U.S.A. owned and operated manufacturers. All of our weapon systems are 100% pure American made.

SIG 556

The Sig 556 is designed to be a gas-operated piston driven rotating bolt design, and chambered in 5.56 NATO / 223 Remington, the Sig 556 rifles are not only reliable, but accurate. The Sig rifle also features ambidextrous controls, as well as ambidextrous safety. With additional features like picatinny flat top, collapsible or folding stocks, flip up sights, and adjustable gas system.

• 5.56 NATO / 223 Remington Flip Up Sights Picatinny Rail Flat Top • Adjustable Collapsable Stock 1:9 Inch Twist 12 Pounds (Empty, No Magazine) • 30 Round Capacity Polymer Foregrip Cold Hammer Forged Barrel • Chrome Lined Barrel Accepts M-16 / M4 / AR-15 Magazines