SAM-R

The Squad Advanced Marksman Rifle (SAM-R) was developed by the United States Marine Corps Warfighting Laboratory (MCWL) following experimentation with the integration of designated marksmen into infantry squads. Armorers at the MCWL selected the M16 platform for the design to maintain commonality in components and ammunition. The Precision Weapons Section of the Weapons Training Battalion at Marine Corps Base Quantico conducted the assembly of the rifles.

The SAM-R is a gas-operated firearm with a rotating bolt, based on the M16A4 pattern. It utilizes a 20-inch stainless steel match-grade heavy barrel with a 1:7 twist, produced by Compass Lake Engineering from Krieger blanks. The design incorporates a Knight’s Armament Company (KAC) Free-Floating Rail Adapter System and a KAC gas block featuring an integrated folding front sight and bayonet lug. Internal features include a PRI M84 Gas Buster charging handle and a Norgon ambidextrous magazine release. The trigger system consists of either an M16A1 assembly or a KAC two-stage match trigger. Primary optics include the Leupold TS-30A2 Mark 4 MR/T and the Marine Corps Rifle Combat Optic ACOG, while the AN/PVS-22 Universal Night Sight is used for night operations. The rifle is typically equipped with a Harris swivel bipod attached via a KAC stud.

The SAM-R served with the United States Marine Corps from 2001 to 2015, seeing use in the Iraq War and the War in Afghanistan. Initial deployments included approximately 100 rifles issued to the 22nd, 24th, and 26th Marine Expeditionary Units of the II Marine Expeditionary Force. A variant known as the "West Coast SAM-R," utilized by the I Marine Expeditionary Force, consisted of standard M16A4 rifles fitted with optics and bipods rather than the accurized specifications of the Quantico-built models. The British Army also reportedly used a small number of the rifles. The Marine Corps replaced the SAM-R in the mid-2010s with the M27 Infantry Automatic Rifle and the M38 Designated Marksman Rifle.