United States Army Squad Designated Marksman Rifle

Infobox Weapon|is_ranged=yes
name=US Army SDM-R


caption= Soldiers from the 3rd Infantry Division with SDM rifles.
origin=flagcountry|United States
type= Designated marksman rifle
designer=
design_date=
service= 2004–present
wars= Operation Enduring Freedom, Operation Iraqi Freedom
cartridge= 5.56x45mm NATO
action= Gas-operated (direct impingement)
rate= Semi-automatic
velocity= convert|3050|ft/s|m/s|abbr=on
range= convert|600|yd|m
maximum_range= convert|600|yd|m
weight= convert|10|lb|kg with optic & fully-loaded 30-round magazine
length= convert|39.5|in|mm
part_length= convert|20|in|mm
feed= 20- or 30-round detachable box magazine|

The United States Army Squad Designated Marksman Rifle (SDM-R) is a heavily modified M16-series rifle that provides increased accuracy over range, giving infantry squads greater firepower.

Background

The addition of an embedded marksman at the platoon or squad level has been a continuing process in the U.S. military. The U.S. Marine Corps (USMC) experimented with this during "Project Metropolis", before creating the "Squad Advanced Marksman" (SAM) position along with the Squad Advanced Marksman Rifle (SAM-R) specifically for this purpose.

The U.S. Army 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 SDM is an integral part of the squad and serves as a rifleman first and designated marksman second. The SDM is not meant to be a squad sniper who engages the enemy with precision fire at extreme ranges, but instead is trained to directly support the squad with well-aimed shots at ranges slightly beyond the normal engagement distances for riflemen.

Much like the U.S. Marine Corps SAM-R, the U.S. Army SDM-R is an accurized M16 rifle (5.56x45mm NATO caliber) built in-house by the U.S. Army Marksmanship Unit (USAMU), and is informally known as "the AMU rifle". SDM-R's have only been built for one major Army division and is not an Army program of record. 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 such as the United States Navy Mark 12 Mod X Special Purpose Rifle (SPR) and the SEAL Recon Rifle.

Task Force Small Arms Readiness Group (TF SARG) conducts the week-long SDM course at the SARG academy at Camp Bullis, Texas. Many of the instructors are President's 100 recipients.

pecifications

*Upper and lower receivers: The rifles are produced by the Army Marksmanship Unit (AMU) at Fort Benning, Georgia using either new semi-automatic ArmaLite lower receivers or existing Army M16A2 or A4 lower receivers previously supplied by either Colt or Fabrique Nationale. All rifles are equipped with a fixed A2 stock and a Knight's Armament Company 2-stage match grade trigger capable of only semi-automatic fire. The upper receivers are flat-top style, but unlike the SAM-R and SPR, they do not have extended feed ramps.

*Barrel: The 1:7 twist, 20-inch barrel from the M16A2 and A4 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 SDM-R retains the A2-style flash hider.

*Sights and optics: The issued optic is a 4x32 Advanced Combat Optical Gunsight (ACOG) (models TA31F, TA01, TA01B, or TA01NSN). A Matech Industries 600-meter backup iron sight is also used.

*Handguard: Daniel Defense M4 Rail 12.0 handguard, with an octagonal steel collar locking it to the upper receiver. The Daniel Defense handguard provides a free-floating MIL-STD-1913 rail forend.

*Bipod: A Harris S-L bipod attached to an ARMS #17 throw-lever 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 examined an alternate version, based on the M4 Carbine. The barrel was to have been an convert|18|in|mm|sing=on long fluted Douglas barrel with 1:8 twist. A mid-length gas system was to be used, along with the Daniel Defense M4Rail 9.0 handguard. This effort never went beyond the staffing process.

Photos

ee also

* U.S. Marine Corps Squad Advanced Marksman Rifle
* U.S. Marine Corps Designated 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
* Civilian Marksmanship Program

External links

* [http://www.usaac.army.mil/amu/Training/training.html USAMU]
* [http://www.odcmp.org/0106/default.asp?page=SDM CMP Squad Designated Marksman Instructor Program]
* [http://www.usaac.army.mil/amu/News/SDM.pdf USAMU SQUAD DESIGNATED MARKSMAN’S COURSE]
* [http://www.globalsecurity.org/military/library/policy/army/fm/3-22-9/c07.htm#sectionvii Field Manual 3-22.9: Squad Designated Marksman training]
* [http://www.danieldefense.com/ Daniel Defense]