United States Army Squad Designated Marksman Rifle
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.
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A recent graduate of the Squad Designated Marksman Instructor Course with a Squad Designated Marksman Rifle. |
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.
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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.
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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.
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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.
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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.
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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.
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.
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.*
U.S. Marine Corps Squad Advanced Marksman Rifle*
SEAL Recon Rifle*
United States Navy Mark 12 Mod X Special Purpose Rifle*
List of individual weapons of the U.S. Armed Forces*
Designated marksman*
Field Manual 3-22.9: Squad Designated Marksman training*
Daniel Defense
