An Mk 12 Mod 0 SPR clone built by Mid-South Tactical Network (MSTN). This specific rifle features the current (and improved) version of the "Crane" Stock which is manufactured by LMT - Lewis Machine and Tool. Also shown is a Harris Bipod with a KMW Pod-Loc.

The United States Navy Mark 12 Mod 0/1 Special Purpose Rifle (SPR) is a rifle that has been in service with the United States special forces in Operation Enduring Freedom and Operation Iraqi Freedom. SPR initially stood for Special Purpose Receiver, but that nomenclature seems to have disappeared as the weapon became a stand alone weapon system, and not just an add on upper as part of proposed SOPMOD upgrades. SPR now means Special Purpose Rifle. It was eventually type classified by the Navy as the Mk 12, though the Army also uses this designation. Download high resolution version (900x390, 137 KB)SPR Rifle File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Download high resolution version (900x390, 137 KB)SPR Rifle File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A rifle is a firearm with a stock and a barrel that has a spiral groove or grooves (rifling) cut into its interior. ... The United States Special Operations Forces is the official category where the United States Department of Defense lists the US military units that have a training specialization in unconventional warfare and special operations. ...     It has been suggested that United States war in Afghanistan be merged into this article or section. ... Combatants Coalition Forces: United States United Kingdom Poland Australia South Korea Romania Spain Portugal Italy others. ... The United States Navy (also known as USN or the U.S. Navy) is the branch of the United States armed forces responsible for conducting naval operations. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Background

This weapon system, used by Special Forces units of both the US Army and US Navy, is a heavily modified deviation from the familiar AR15/M16 line of infantry weapons, and thus is chambered for NATO standard 5.56 x 45 mm caliber ammunition. It serves a light sniper/designated marksman role. The SPR was originally proposed by Mark Westrom, currently president of Armalite, while at the Rock Island Arsenal. The SPR program was an outgrowth of the desire by both US Army and Navy special forces for a rifle with greater effective range than an M4 type Carbine but still shorter in length than a standard issue M16A2/A4. The SPR program appears to have grown out of both the SOPMOD Block II program, and the US Navy SEALs 'Recon Rifle' (a 16" flat-topped AR-15/M16 Carbine). The Naval Surface Warfare Center, Crane Division (often referred to as NSWC-Crane or just Crane) essentially expanded on the Recon Rifle, an idea that some SEALs maintain was a waste of energy and money. This article or section should include material from Colt AR-15 SP1 ar-15. ... M16 is the U.S. military designation for a family of rifles derived from the ArmaLite AR-15 and further developed by Colt. ... NATO 2002 Summit in Prague The North Atlantic Treaty Organisation[1] (NATO), also called the North Atlantic Alliance, the Atlantic Alliance or the Western Alliance, is an international organisation for collective security established in 1949, in support of the North Atlantic Treaty signed in Washington, DC, on 4 April 1949. ... U.S. Military 5. ... Looking through a USMC sniper rifles scope at a practice range at Camp Hansen The same USMC sniper team, with a M40 Sniper Rifle (2004) The term sniper is attested from 1824 in the sense of sharpshooter. The verb to snipe originated in the 1770s among soldiers in British India... The Designated Marksman (DM) is a military role in a U.S. infantry squad. ... ArmaLite, originally the ArmaLite Division of the Fairchild Engine and Airplane Corporation, is one of the most influential corporations in the history of 20th century small arms. ... RIA is a company located in the Phillipines. ... Background Built in house by SEAL Team armorers, and later by the Naval Surface Warfare Center, Crane Division (often referred to as NSWC-Crane or just Crane), these rifles were developed to provide SEAL snipers with a portable, lightweight system that had greater lethality over a standard M4-type AR... Naval Surface Warfare Center Crane Division is a United States Navy installation located approximately 70 miles (113 km) southwest of Indianapolis, Indiana and predominantly located in Martin County. ...

The exact history of the Mk 12 is still something under debate, but its become apparent that there are between four and five prime iterations of the weapon, culminating in the last Mk 12 Mod 1 version. One progression has four models: SPR Proto 1, SPR Proto 2, Mk 12 Mod 0 and Mk 12 Mod 1. The other progression is: SPR, SPR/A, SPR/B, Mk 12 Mod 0, and Mk 12 Mod 1 (all as separate iterations). The specifications entered will follow the second progression.

There is also increasing agreement among observers and small-arms historians that different US military service branches generally deploy different iterations of the SPR. Available evidence, including both US DOD photographs and privately-obtained photographs (like the ones shown below), consistently show most US Army SOF units using the Mk 12 Mod 0 iteration of the SPR, while NAVSPECWAR operators and US Army Rangers have both been identified as using the Mk 12 Mod 1 version.

It has also been reported that more Mod 1 versions have been issued than Mod 0 versions across USSOCOM, and that last SPRs procured by USSOCOM were all Mod 1s. Speculation exists as to whether or not the Mod 1 is considered to have "replaced" the Mod 0, as the Mod 1 requires significantly fewer parts than the Mod 0 (due to the Mod 0's more complex PRI/ARMS forearm assembly and its barrel-mounted PRI front sight assembly).

Though the Mark 12 Mod 0 Special Purpose Rifle had enjoyed relative obscurity for most of its short life, recently it has been featured prominently both in media photos of the Iraq conflict and in interactive video games such as the government-created title America's Army: Special Forces, the console title Tom Clancy's Ghost Recon 2, and the freeware first-person shooter True Combat: Elite. This article is about computer and video games. ... A video game console is a dedicated electronic machine designed to play video games. ... Screenshot from the Xbox version of Ghost Recon 2 Tom Clancys Ghost Recon 2 (also known as Ghost Recon 2) was originally announced in a Ubisoft press release dated April 8, 2004, and was released in North America for the Xbox video game console on November 30, 2004. ... This article or section does not cite its references or sources. ...

SPR rifles and their use have also been documented in several popular gun magazines over the past few years, including Soldier of Fortune (which included a cover-shot of a Mod 1 on its January 2004 issue); Guns & Ammo's Combat Tactics magazine, Special Weapons for Military and Police magazine, and several others.

In a civilian capacity, copies (commonly called "SPR clones") of the SPR rifle have also become quite popular among shooters and collectors in the US, with several reputable builders of AR15-style rifles making civilian-legal copies of this very accurate rifle.

Specifications

• Upper Receiver: The upper receiver blocks themselves were initially supplied by Colt, with some of those being from Diemaco as well (Colt has been outsourcing parts of its production to the Canadian firm for a while now—Colt purchased Diemaco in February 2005, but continues to supply firearms under both names). There is a debate about whether the upper blocks for the Mk 12 rifles, though, came solely from Armalite, or were a mix of receivers from Armalite and Colt/Diemaco. All of these upper receivers were flat top, but have been seen both with the old style tear drop forward assist and the new round style. There is, however, no obvious consistency in this regard.

• Lower Receiver: When the SPR program was still in the phase where it was just a receiver, Crane assembled all of its prototypes using either M16A1 or M4A1 lowers. It is unknown whether this pattern continued as the program progressed. There is also some issue about whether, when the Navy type-classified the weapon, Precision Reflex Incorporated (PRI) began assembling the rifles themselves. While a number of options were tried in the end, a Knight's Armament Company (KAC) 2-stage trigger was finally decided upon as the standard fit.

• Barrel: A 18 in (457 mm) threaded-muzzle match-grade free floating stainless steel heavy barrel with a 1:7 in (178 mm) rifle twist ratio. The barrels have a special contour to maximize accuracy and minimize weight; they are manufactured by Douglas Barrels. An OPS Inc. muzzle brake and collar (to align the OPS Inc. 12th Model Suppressor) is installed with the barrel. These barrels were designed to take advantage of the new Mk 262 cartridge, which uses a 77 grain (5 g) bullet, that is now being fielded.

• Buttstock: SPRs in action have been seen with a number of mil-spec buttstocks including M16A1 buttstocks, M16A2 buttstocks, retractable M4 buttstocks (both the older 4-position stock and the newer 6-position type) , and the Crane Enhanced retractable buttstock. It is readily compatible with any type of stock system developed for the AR-15 weapon system and US SOF operator modification/customization of such systems is not uncommon.

• Handguards: In all cases a free floating forearm is utilized. This handguard does not ever touch the barrel, increasing the accuracy of the weapon by removing increased vibration exerted on the barrel by the rest of the gun. The first SPRs use a PRI Gen I or Gen II carbon-fiber free-float tubes. The SPR/A, SPR/B, and Mk 12 Mod 1 all use the Knights Armament Company (KAC) M4 Match Free-Floating RAS (Rail Adapter System). The Mk 12 Mod 0 uses PRI Gen III free-float tubes. The Gen I and Gen II Freefloat Forearms are combined with the Atlantic Research Marketing Systems (ARMS) #38 SPR MOD Sleeve, while the Gen III Freefloat Forearm, due its it larger barrel nut, only works with the ARMS #38 SPR PEQ-2-3.

• Sights: The original SPR used an early PRI flip-up front sight with an elevation dial, which has since been discontinued. The Mk 12 Mod 0 uses the current PRI flip-up front sight. The SPR/A, SPR/B, and Mk 12 Mod 1 use the KAC rail foreend flip-up front sight. The SPR and Mk 12 Mod 0 use the ARMS #40 flip up rear sight. The rest of the models use the KAC 600 meter flip up rear.

• Optics: Due to the relative modularity of the system, optics (as well as almost everything else) can be mounted per the operator's wishes, however, this weapon system is most often seen with a 3.5–10×40 mm Leupold LR M3 (SPR/A), a 2.5–9×36 mm TS-30 (SPR/B), or a 3–9×36 mm TS-30 A2 (Mk 12 Mod 0/1) Mid Range/Tactical Illuminated Reticle Dayscope (civilian versions are known as the Leupold Mark 4 MR/T 3–9×36). Given NAVSPECWAR's contract with Nightforce Optics, it is also expected that some NAVSPECWAR-fielded SPRs will be fitted with Nightforce's 2.5-10x24NXS scope. Night vision devices can also be attached. These scopes usually come with flip open dust covers and a honeycomb anti-glare anti-reflection device (ARD).

• Mounts: As mentioned before, a long accessory rail, called a SWAN Sleeve (ARMS SPR MOD or ARMS #38 SPR PEQ-2-3), manufactured by ARMS, is installed, running the length of the rifle. The SPR/A and SPR/B both used the KAC M4 Match FF RAS. Two ARMS #22 Throwlever 30 mm steel rings are used to mount the dayscope. The SPR/A, SPR/B, and Mk 12 Mod 1 use ARMS #22 high rings, while due to the increased height from the SWAN Sleeve, the SPR and Mk 12 Mod 0 use ARMS #22 medium rings. An under-the-handguard ARMS #32 Throwlever mount is used to mount the Harris bipod (the ARMS #42 Throwlever mount is used to mount the Versa-Pod); this features a quick release action.

• Bipod: Originally Versa-Pods, a cheaper Chinese-made copy of the relatively expensive Parker-Hale swivel bipod, were used, but were taken off the system after the initial SPR. Currently, a Harris swivel model bipod is typically used with the SPR, and is sometimes seen with a KMW Pod-Loc tension adjustment device. As mentioned above, the bipod is mounted via a ARMS #32 throwlever device attached to the bottom rail of the rifle's forearm. The ARMS mount is used on both Mod 0 and Mod 1.

• Suppressor: The suppressor threads directly onto the OPS Inc. muzzle brake and uses the collar to stay centered. It is an OPS Inc. 12th Model SPR Muzzle Brake Suppressor (MBS).

• Ammunition: The SPR is not used to fire standard issue M855 ball or M856 tracer (and even less so M193 ball). Due to the limits in performance and poor accuracy of the 62 grain (4 g) M855 ball (standard NATO green-tip .223), the Mark 262 Open Tip Match (OTM) round was developed as a more accurate 5.56 × 45 mm round. The cartridges are made by Black Hills Ammunition. The first production batches were designated the Mk 262 Mod 0 and used a Sierra Bullets MatchKing 77 grain (5 g) Hollow Point Boat Tail (HPBT) bullet without a cannelure (crimping groove). Black Hills then approached Nosler, who made a similar 77gr OTM bullet, and Nosler agreed to supply cannelured bullets to Black Hills. This load was designated Mk 262 Mod 1. Recently, Sierra agreed to add a minimal crimp to their bullet, and this has since replaced the Nosler bullet in the current versions of Mk 262 Mod 1.

Diemaco is a Canadian firearms and defence company. ... M16 is also the Eagle Nebula in astronomy. ... Caliber: 5. ... Knights Armament Company (KAC, also Knights Manufacturing Company) is an American firearms and firearms parts manufacturer. ... The muzzle brake of the 105 mm gun on an AMX 10 RC fighting vehicle. ... Knights Armament Company (KAC, also: Knights Manufacturing Company) is an American firearms parts manufacturer owned by C. Reed Knight, based in Titusville, Florida (moved from old facility at Vero Beach, Florida) and best known for producing Rail Interface System (RIS) and Rail Adapter System (RAS) grips for military... An example of a barrel nut A barrel nut is a type of screw which is internally threaded and has a slotted head. ... Black Hills Ammunition is an ammunition and reloading supplies manufacturing company that has developed a reputation for very accurate, very standardized ammunition in a varied multitude of calibers. ... John Nosler realized that rifle bullet performance was sadly lacking. ...

Photos

An SPR/A w/ fixed stock, Harris bipod, and the KAC M4 Match FF RAS. Profile shot of a SPR/A File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...	An SPR/B setup similarly to the SPR/A to the left. The SPR/A and SPR/B only differ on the type of scope used. Profile Shot of a SPR/B File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...	Another US Army SF operator carrying is OD green painted Mk 12 Mod 0. The exposed front end of the rifle details the OPS Inc. muzzle brake, the Versa-Pod bipod (folded) and an Insight Technologies AN/PEQ-2A illuminator mounted on the side of the handguards. Mk 12 Mod 0 SPR w/ Muzzle Break - US Army SF Carrying - Government Photo File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The AN/PEQ-2 is a laser aiming device for use on rifles fitted with a Picatinny rail. ...	An SPR with a full M16 riflestock and various night vision optics attached. Mk 12 Mod 0 SPR w/ Optics - Government Photo File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
A US Army SF operator shows his Filipino counterparts the SPR. This one also has a full M16 riflestock, has the OPS Inc. silencer attached, and is camouflage painted. Mk 12 Mod 0 SPR w/ Silencer - US Army SF demonstrating to Filipino military - Government Photo File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...	A US Army SF operator takes aim with his desert camouflage painted SPR. An Insight Technologies AN/PEQ-2A Target Pointer/Illuminator Aiming Light (TIPAL) is mounted on the right of the rifle's handguards. A standard M4 telescoping stock is used on this one. Mk 12 Mod 0 SPR w/ Silencer - US Army SF Firing - Government Photo File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The AN/PEQ-2 is a laser aiming device for use on rifles fitted with a Picatinny rail. ...	An SPR, not a Mk 12 Mod 0. Note the early PRI freefloat tube of constant diameter. This SPR has a Versa-pod bipod and has a fixed stock. The upper receiver block has a teardrop-shaped forward assist. Download high resolution version (880x286, 66 KB) Profile Shot of an early SPR File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

See also

• United States Navy Mark 11 Mod 0 Sniper Weapon System
• SEAL Recon Rifle
• Knight's Armament Company
• KAC SR-25
• United_States_Army_Squad_Designated_Marksman_Rifle
• U.S. Marine Corps Squad Advanced Marksman Rifle
• U.S._Marine_Corps_Designated_Marksman_Rifle

Image:Http://av. ... Background Built in house by SEAL Team armorers, and later by the Naval Surface Warfare Center, Crane Division (often referred to as NSWC-Crane or just Crane), these rifles were developed to provide SEAL snipers with a portable, lightweight system that had greater lethality over a standard M4-type AR... Knights Armament Company (KAC, also Knights Manufacturing Company) is an American firearms and firearms parts manufacturer. ... The SR-25 is a semi-automatic sniper rifle based on the Stoner AR-10. ... The United States Army Squad Designated Marksman Rifle (SDM-R) is a M16-series rifle modified to provide increased accuracy over range, giving infantry squads greater firepower. ... A Squad Advanced Marksman of the 22nd MEU in Afghanistan The Squad Advanced Marksman Rifle (SAM-R) gives U.S. Marines the capability to provide precision fire in support of the rifle squad, providing precision fire in support of an assault, and aid in observation and adjusting of supporting arms. ... The United States Marine Corps Designated Marksman Rifle (DMR, NSN 1005-01-458-6235) is a semi-automatic gas-operated rifle chambered for the 7. ...

External links

• AR15.com
• Mid-South Tactical Network
• Atlantic Research Marketing Systems, Inc.
• Sierra Bullets
• OPS, Inc. Muzzle Brakes and Suppressors