United States Army Squad Designated Marksman Rifle
Encyclopedia
The United States Army Squad Designated Marksman Rifle (SDM-R) is a heavily modified M16
-series semi-automatic rifle
intended to provide increased accuracy over range, giving infantry
squad
s greater firepower.
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 3rd Infantry Division 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 3rd Infantry division SDM-R was an accurized
M16 rifle
(5.56x45mm NATO
caliber) built in-house by the U.S. Army Advanced Marksmanship Unit, and was 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
.
The National Guard Marksmanship Training Center of the Arkansas Army National Guard
conducts the fourteen day long Squad Designated Marksman Course at Camp Joseph T. Robinson. Soldiers fire over 1500 rounds from the M16A4 rifle under the close supervision of course cadre.
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.
. The barrel was to have been an 18 inches (457.2 mm) 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.
The Designated Marksman Equation
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
-series semi-automatic rifle
Semi-automatic rifle
A semi-automatic rifle is a type of rifle that fires a single bullet each time the trigger is pulled, automatically ejects the spent cartridge, chambers a fresh cartridge from its magazine, and is immediately ready to fire another shot...
intended to provide increased accuracy over range, giving infantry
Infantry
Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...
squad
Squad
In military terminology, a squad is a small military unit led by a non-commissioned officer that is subordinate to an infantry platoon. In countries following the British Army tradition this organization is referred to as a section...
s greater firepower.
Background
The addition of an embedded marksmanMarksman
A marksman is a person who is skilled in precision, or a sharpshooter shooting, using projectile weapons, such as with a rifle but most commonly with a sniper rifle, to shoot at long range targets...
at the platoon
Platoon
A platoon is a military unit typically composed of two to four sections or squads and containing 16 to 50 soldiers. Platoons are organized into a company, which typically consists of three, four or five platoons. A platoon is typically the smallest military unit led by a commissioned officer—the...
or squad
Squad
In military terminology, a squad is a small military unit led by a non-commissioned officer that is subordinate to an infantry platoon. In countries following the British Army tradition this organization is referred to as a section...
level has been a continuing process in the U.S. military
Military of the United States
The United States Armed Forces are the military forces of the United States. They consist of the Army, Navy, Marine Corps, Air Force, and Coast Guard.The United States has a strong tradition of civilian control of the military...
. The U.S. Marine Corps
United States Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...
(USMC) experimented with this during Project Metropolis, before creating the "Squad Advanced Marksman" (SAM) position along with the Squad Advanced Marksman Rifle
U.S. Marine Corps Squad Advanced Marksman Rifle
The Squad Advanced Marksman Rifle is a semi-automatic rifle developed by and in service with the United States Marine Corps. It gives 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...
(SAM-R) specifically for this purpose.
The 3rd Infantry Division 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
Rifleman
Although ultimately originating with the 16th century handgunners and the 17th century musketeers and streltsy, the term rifleman originated from the 18th century. It would later become the term for the archetypal common soldier.-History:...
first and designated marksman
Designated marksman
The designated marksman is a military marksman role in a U.S. infantry squad. The term sniper was used in Soviet doctrine although the soldiers using the Dragunov were the first to use a specifically designed designated marksman's rifle. Sniper is also used in Russian doctrine...
second. The SDM is not meant to be a squad sniper
Sniper
A sniper is a marksman who shoots targets from concealed positions or distances exceeding the capabilities of regular personnel. Snipers typically have specialized training and distinct high-precision rifles....
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 3rd Infantry division SDM-R was an accurized
Accurizing
Accurizing is the process of improving the accuracy of a firearm or airgun.For firearms, accuracy is defined as the ability to hit exactly what one is aiming at...
M16 rifle
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
(5.56x45mm NATO
5.56x45mm NATO
5.56×45mm NATO is a rifle cartridge developed in the United States and originally chambered in the M16 rifle. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries. It is derived from, but not identical to, the .223 Remington cartridge...
caliber) built in-house by the U.S. Army Advanced Marksmanship Unit, and was 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
United States Special Operations Command
The United States Special Operations Command is the Unified Combatant Command charged with overseeing the various Special Operations Commands of the Army, Air Force, Navy and Marine Corps of the United States Armed Forces. The command is part of the Department of Defense...
that led to the development of weapons such as the United States Navy Mark 12 Mod X Special Purpose Rifle
United States Navy Mark 12 Mod X Special Purpose Rifle
The United States Navy Mark 12 Mod 0/1 Special Purpose Rifle is a rifle in service with United States Special Operations Forces in Operation Enduring Freedom and Operation Iraqi Freedom...
(SPR) and the SEAL Recon Rifle
SEAL Recon Rifle
Built in-house by U.S. Navy SEAL Team armorers, and later by the Naval Surface Warfare Center, Crane Division , the SEAL Recon Rifle was developed to provide SEAL snipers with a portable, lightweight system with greater lethality than a standard M4 carbine...
.
The National Guard Marksmanship Training Center of the Arkansas Army National Guard
Arkansas Army National Guard
The Arkansas Army National Guard is a component of the Arkansas National Guard and the United States National Guard. Nationwide, the Army National Guard comprises approximately one half of the US Army's available combat forces and approximately one third of its support organization...
conducts the fourteen day long Squad Designated Marksman Course at Camp Joseph T. Robinson. Soldiers fire over 1500 rounds from the M16A4 rifle under the close supervision of course cadre.
Task Force Small Arms Readiness Group (TF SARG) conducts the week-long SDM course at the SARG academy at Camp Bullis
Camp Bullis
Camp Bullis Military Training Reservation is a U.S. Army training camp located in Bexar County, Texas, just northwest of San Antonio, USA. The camp is named for Brigadier General John Lapham Bullis ,...
, Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. Many of the instructors are President's 100
President's Hundred Tab
The President's Hundred Tab is a badge awarded by the National Rifle Association to the 100 top-scoring military and civilian shooters in the President's Pistol and President's Rifle Matches. The tab is authorized for wear on military uniforms of the U.S. Army, U.S. Navy , and U.S. Coast Guard...
recipients.
Specifications
- Upper and lower receivers: The rifles were produced by the Army Marksmanship Unit (AMU) at Fort BenningFort BenningFort Benning is a United States Army post located southeast of the city of Columbus in Muscogee and Chattahoochee counties in Georgia and Russell County, Alabama...
, Georgia using either new semi-automatic ArmaLiteArmaLiteArmaLite is the name of a small arms engineering facility founded in the early 1950s, and once associated with the Fairchild Engine and Airplane Corporation. ArmaLite was formally incorporated as a subdivision of Fairchild on October 1, 1954...
lower receiversReceiver (firearms)In firearms terminology, the receiver is the part of a firearm that houses the operating parts. The receiver usually contains the bolt carrier group, trigger group, and magazine port. In most handguns, the receiver, or frame, holds the magazine well or rotary magazine as well as the trigger mechanism...
or existing Army M16A2 or A4 lower receivers previously supplied by either ColtColt's Manufacturing CompanyColt's Manufacturing Company is a United States firearms manufacturer, whose first predecessor corporation was founded in 1836 by Sam Colt. Colt is best known for the engineering, production, and marketing of firearms over the later half of the 19th and the 20th century...
or Fabrique Nationale de HerstalFabrique Nationale de HerstalFabrique Nationale d'Herstal — self identified as FN Herstal and often referred to as Fabrique Nationale or simply FN — is a firearms manufacturer located in Herstal, Belgium....
. All rifles were equipped with a fixed A2 stockStock (firearm)A stock, also known as a buttstock or shoulder stock, is a part of a rifle or other firearm, to which the barrel and firing mechanism are attached, that is held against one's shoulder when firing the gun. Stocks are also found on crossbows though a crossbow stock is more properly referred to as a...
and a Knight's Armament CompanyKnight's Armament CompanyKnight's Armament Company is an American firearms and firearms parts manufacturer.It is owned by C. Reed Knight and based in Titusville, Florida. KAC is best known for producing the Rail Interface System and the Rail Adapter System grips for military firearms...
2-stage match gradeMatch gradeMatch grade frequently refers to firearm parts and ammunition that are suitable for a competitive match. Sometimes, it also refers to other devices and parts that are made with high precision in mind....
trigger capable of only semi-automaticSemi-automatic rifleA semi-automatic rifle is a type of rifle that fires a single bullet each time the trigger is pulled, automatically ejects the spent cartridge, chambers a fresh cartridge from its magazine, and is immediately ready to fire another shot...
fire. The upper receivers were flat-top style, but unlike the SAM-R and SPR, they did not have extended feed ramps.
- Barrel: The 1:7 twist, 20 inches (508 mm) barrelGun barrelA gun barrel is the tube, usually metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity....
from the M16A2 and A4 were replaced with a stainless steelStainless steelIn metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
Douglas Barrels 1:8 twist, 20-inch barrel, with 12 flutes cut into the barrel to reduce weight. The front sight block was installed with 4 set screws instead of two taper pins. The SDM-R retained the A2-style flash hiderFlash suppressorA flash suppressor, also known as a flash guard, flash eliminator, flash hider, or flash cone, is a device attached to the muzzle of a rifle or other gun that reduces the visible signature of the burning gases that exit the muzzle. This reduces the chances that the shooter will be blinded in dark...
.
- Sights and optics: The issued opticTelescopic sightA telescopic sight, commonly called a scope, is a sighting device that is based on an optical refracting telescope. They are equipped with some form of graphic image pattern mounted in an optically appropriate position in their optical system to give an accurate aiming point...
was a 4x32 Advanced Combat Optical GunsightAdvanced Combat Optical GunsightAdvanced Combat Optical Gunsights are a series of telescopic sights manufactured by Trijicon. The ACOG is designed to be used on the M16 rifle and M4 carbine, but Trijicon has developed ACOG accessories for certain other firearms...
(ACOG) (models TA31F, TA31RCO, TA01, TA01B, or TA01NSN). A Matech Industries 600-meter backup iron sightIron sightIron sights are a system of shaped alignment markers used as a sighting device to assist in the aiming of a device such as a firearm, crossbow, or telescope, and exclude the use of optics as in telescopic sights or reflector sights...
was also used.
- Handguard: Daniel Defense M4 Rail 12.0 handguard, with an octagonal aluminum collar locking it to the upper receiver. The handguard provides a free-floating Picatinny railPicatinny railThe Picatinny rail or MIL-STD-1913 rail or STANAG 2324 rail or a "Tactical Rail" is a bracket used on some firearms in order to provide a standardized mounting platform. A similar system is the Weaver rail mount.-Description:...
forend.
- Bipod: A Harris S-L bipodBipodA bipod is a support device that is similar to a tripod or monopod, but with two legs. It provides significant stability along two axes of motion .-Firearms:...
attached to an ARMS #17 throw-lever rail mount was mounted to the underside of the handguard. Since the handguard was free-floating, it did not come into contact with the barrel, and any pressure from the bipod on the handguard did not deflect the barrel.
Variants
The 82nd Airborne Division examined an alternate version, based on the M4 carbineM4 carbine
The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16, all based on the original AR-15 designed by Eugene Stoner and made by ArmaLite. It is a shorter and lighter variant of the M16A2 assault rifle, with 80% parts commonality.It is a gas-operated,...
. The barrel was to have been an 18 inches (457.2 mm) long fluted
Fluting (firearms)
In firearms terminology, fluting refers to the removal of material from a cylindrical surface, usually creating grooves. This is most often the barrel of a rifle, though it may also refer to the cylinder of a revolver or the bolt of a bolt action rifle....
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.
See also
- U.S. Marine Corps Squad Advanced Marksman RifleU.S. Marine Corps Squad Advanced Marksman RifleThe Squad Advanced Marksman Rifle is a semi-automatic rifle developed by and in service with the United States Marine Corps. It gives 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...
- United States Marine Corps Designated Marksman Rifle
- SEAL Recon RifleSEAL Recon RifleBuilt in-house by U.S. Navy SEAL Team armorers, and later by the Naval Surface Warfare Center, Crane Division , the SEAL Recon Rifle was developed to provide SEAL snipers with a portable, lightweight system with greater lethality than a standard M4 carbine...
- United States Navy Mark 12 Mod X Special Purpose RifleUnited States Navy Mark 12 Mod X Special Purpose RifleThe United States Navy Mark 12 Mod 0/1 Special Purpose Rifle is a rifle in service with United States Special Operations Forces in Operation Enduring Freedom and Operation Iraqi Freedom...
- List of individual weapons of the U.S. Armed Forces
- Designated marksmanDesignated marksmanThe designated marksman is a military marksman role in a U.S. infantry squad. The term sniper was used in Soviet doctrine although the soldiers using the Dragunov were the first to use a specifically designed designated marksman's rifle. Sniper is also used in Russian doctrine...
- Civilian Marksmanship ProgramCivilian Marksmanship ProgramThe Civilian Marksmanship Program is a U.S. government-chartered program that promotes firearms safety training and rifle practice for all qualified U.S. citizens with special emphasis on youth. Any U.S. citizen who is not legally prohibited from owning a firearm may purchase a military surplus...
External links
- USAMU
- CMP Squad Designated Marksman Instructor Program
- USAMU SQUAD DESIGNATED MARKSMAN’S COURSE
- Field Manual 3-22.9: Squad Designated Marksman training
The Designated Marksman Equation