The L129A1 is categorized as a "Designated Marksman Rifle" (DMR) which places it between an assault rifle and a dedicated sniper rifle. As such, the designated marksman himself offers up, to an extent, the inherent benefits of both types of warfighters - able to supply self-loading, repeating fire to the enemy at ranges that go beyond that of the standard assault rifle. The designated marksmen is, however, not trained in the finer points of a sniper element and, instead, carries battlefield skills more akin to the regular fighting soldier. The United States developed their "designated marksman" component through its unfolding experiences in the Afghanistan and Iraq theater and was able to properly develop complementary weaponry through its well-established programs and facilities for use by the Army and Marine. When the British Army attempted to follow suit, it realized that it lacked the proper weaponry for the role - their smaller-caliber standard-issue L85 assault rifles were not up to the task particularly when attempting to counter enemies at distance armed with light machine guns - or the proper in-house facilities to make the proper weapon a reality. It was, therefore, decided that a new weapon system chambered for the larger 7.62mm cartridge be acquired, a weapon that also exhibited several other qualities the MoD required including ease of maintenance, ease of operation requiring only basic gunnery training, a compact profile for transportation or scouting sorties and - of course - repeat accuracy against human-sized targets at range.
The MoD set about creating an internal sharpshooter program to which Lewis Machine & Tool submitted a modified form of their excellent 7.62mm LM308MWS rifle. After an extensive evaluation process, the L129A1 was selected for further consideration as it managed to hit "on target" in successive shots which bode extremely well for the product. Additionally, LMT harbored its own certified manufacturing facilities which certainly helped its proposal. The LM308MWS was pitted against top contenders in the German Heckler & Koch HK417 and the Belgian Fabrique-National SCAR-17. The end result saw the LM308 accepted as the newest British Army firearm to come along in decades - designated in the British Army inventory as the "L129A1" and modified for the rigors of combat.
Outwardly, the L129A1 is of a most conventional layout. Construction utilizes heavy duty metal components as well as lightweight, corrosion-resistant polymers. The receiver contains all of the required internal functions as well as external firing selectors along both sides (near the pistol grip) for true ambidextrous use. There are two modes of fire - "safety" and "semi-automatic" denoted by a red and white decal at the selector position. The charging handle and ejection port are set to the right side of the receiver, favoring right-handed shooters but also keeping the ejecting cartridges well away of the firer's face. The firing operation involves the tried-and-true direct gas impingement system common to other firearms of this class. The pistol grip and trigger unit follow a very traditional M16-like appearance with the grip being well-angled to the rear and ergonomically designed for a firm hold. The 20-round straight detachable, spring-loaded magazine feeds just ahead of the trigger unit. There is a shrouded forend for a second-hand hold and this is ribbed for sure grip. The long running receiver and forend area is home to a Picatinny rail system to which optics of several types can be affixed (with backup sights provided for by Knight's Armament Company). The standard-issue scope for the British Army concerning the L129A1 is the Trijicon 6x48mm ACOG with a BDC reticle. Additionally, accessory rails are present along the forend sides and underside, the latter allowing the installation of a basic forward grip for improved support. The SOPMOD-style stock is supported by a tubular base and extends to a fully-molded shoulder support - the stock being adjustable to six preset positions. The 16-inch stainless steel, free-floating barrel protrudes from the vented forend shroud and is capped by a muzzle compensator/flash suppressor adapter. Of note is that the barrel is fully removable "in-the-field" and can be changed as needed. The LMT is delivered in a hard foam-padded case that includes the rifle itself, eight magazines (manufactured by Knight's Armament Company) and a cleaning kit.
The British Ministry of Defense (MoD) has selected the L129A1 to replace its Accuracy International L96 series of bolt-action rifles in use by its designated marksmen. While a quality rifle in its own right, the system does not fit properly into the rather defined role of the DMR. As of this writing (2012), the MoD has ordered (and presumably already received) some 440 L129A1 systems.