United States Army Squad Designated Marksman Rifle

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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 recent graduate of the Squad Designated Marksman Instructor Course with a Squad Designated Marksman Rifle.

Contents

1 Background
2 Specifications
3 Variants
4 Photos
5 See also
6 External links

Background

The desire to have an embedded marksman at the platoon or squad level seems to be something appearing across the board in the U.S. military. The United States Marine Corps (USMC) experimented heavily with this during Project Metropolis, before creating the Squad Advanced Marksman position and creating a rifle specifically for them. The U.S. Army has followed suit in implementing a training program to have one marksman per squad, the Squad Designated Marksman (SDM), and developing a rifle, the Squad Designated Marksman Rifle (SDM-R). The Squad Designated Marksman is an integral part of the squad and serves as rifleman first and designated marksman second. The SDM is not meant to be a squad sniper that engages with precision fire at extreme ranges. Instead, the soldier is trained to directly support the squad with well-aimed shots at ranges slightly beyond the normal engagement distances for riflemen.

Much like the USMC's Squad Advanced Marksman Rifle (SAM-R), the SDM-R is an accurized AR-15/M16-type rifle (5.56 x 45 mm NATO caliber) built in-house by the U.S. Army Marksmanship Unit (USAMU; this rifle is also known informally as "the AMU rifle"). The SDM-R is designed to provide engagement capability at the squad level to 600 meters, similar to the needs expressed by members of USSOCOM that led to the development of weapons like the Mk 12 Mod 0/1, the SEAL's Recon Rifle. Similar needs have also been identified by the USMC, which led to a similar development to the SDM-R in the USMC SAM-R.

Specifications

AR-15-related firearm articles:

AR-10, AR-15
M16/A1/A2/A3/A4
M4/A1 Carbine
Diemaco C7, C8
Colt Commando, XM177, CAR-15
M231 FPW
SDM-R, SAM-R
Mark 11 'SWS'
Mark 12 'SPR'
SEAL Recon Rifle
Mark 18 'CQBR'
Ares Shrike
La France M16K
KAC SR-25

Upper and lower receivers: from most reports the rifles appear to have been built up using existing lower receivers in inventory. What this means is the rifles are completed using A2/A4 lower receivers previously supplied by either Colt or Fabrique Nationale, with a fixed A2 stock. The upper receivers are flat-top style. Unlike the SAM-R and SPR, it does not have extended feed ramps. The trigger has been replaced with a Knight's Armament Company 2-stage match grade trigger capable of only semi-automatic fire.

Barrel: the traditional 1:7 twist, 20-inch barrel has been replaced with a stainless steel Douglas 1:8 twist, 20-inch barrel, with 12 flutes cut into the barrel to reduce weight. The front sight block is installed with 4 set screws instead of two taper pins. The A2-style flash hider is retained.

Sights and optics: the issued optic is a 4x32 ACOG (TA31F, TA01, TA01B, or TA01NSN). A Matech Industries 600-meter backup iron sight is also used.

Handguard: the SDM-R uses a Daniel Defense M4Rail 12.0 handguard, with an octagonal steel collar locking it to the receiver block. The Daniel Defense handguard provides a free-floating MIL-STD-1913 rail forend.

Bipod: a Harris S-L bipod on ARMS #17 throw rail mount is mounted to the underside of the handguard. Since the handguard is free-floating, it does not come into contact with the barrel, and any pressure from the bipod on the handguard will not deflect the barrel.

Variants

The 82nd Airborne Division uses an alternate version, based on the M4 Carbine. The barrel is an 18-inch long fluted Douglas barrel with 1:8 twist. A mid-length gas system is used, along with the Daniel Defense M4Rail 9.0 handguard.

Photos

Image:SquadDesignatedMarksmen.jpg|A pair of soldiers from the 3rd Infantry Division with SDM rifles. They use TA31F ACOGs. The rifle on the right has an AN/PEQ-2 illuminator with the tape switch attached to the magwell. Image:ArmySnipersinIraq.jpg|The soldier on the left has had his SDM rifle painted. He has a TA01NSN ACOG.

External links