The M42A Scope Rifle was a pulse–action semi–automatic sniper rifle manufactured by Armat Battlefield Systems and employed as the primary sniper weapon of the United States Colonial Marine Corps.


Although visually very different, the M42A has a high degree of parts commonality with the M41A Pulse Rifle; internally, the weapon uses the same rotating breech and feed assembly, although it is chambered for slightly larger and more powerful 10×28mm Caseless ammunition.[1] The weapon's bullpup configuration gives the maximum barrel length (81 cm) while maintaining a compact profile overall. The weapon is constructed from a duratel frame covered by an titanium-aluminide casing. The rifle's stock is fully adjustable to the individual scout sniper.[1] A folding bipod is mounted above the barrel, which is free-floating and contained within a protective shroud and receiver housing. An optional flash suppressor or muzzle break can also be fitted.[1] The rifle is fed from a 15-round magazine located behind the thumbhole grip.

Scout-sniper in ghillie suit with M42A

A USCM scout sniper in a ghillie suit with an M42A Scope Rifle.

The rifle is a key component of battalion operations. Its long range and precision extends the tactical zone of control by up to kilometre or more, subject to local terrain. The rifle is typically issued on a scale of one per company, though it is usually reserved for use in a battalion-controlled pool of up to four scout snipers.[1] As well as their rifle, USCM snipers are typically also equipped with a custom ghillie suit, featuring an outer layer of natural-fiber camouflage over radar-absorbent materials. Ghillie suits can additionally be used in conjunction with a portable heat sink that helps to regulate the suit's thermal signature and thereby camouflage the user against infrared scanning.[2]


The M42A is equipped with a combined multi-spectral passive sensor scope offering twenty times magnification.[1] The scope display shows a composite image based on visual, infrared and electromagnetic emissions. The scope display can be augmented by input from the local sensor matrix via a digital comms broadcast or direct optic cable link; M314 Motion Trackers, ground radar, lidar and IR sensors may all be linked into the rifle.[1] Furthermore, the optional PARGET control system — exact details of which remain classified — is apparently able to connect the rifle into local sentry gun matrix, allowing the scout sniper to redirect sentry gun firing arcs to a desired target.[1]


M252 High Explosive Armor Piercing (HEAP) round: An explosive-tipped match-standard round with a maximum effective range of 2,950 meters. Fusing is variable, and can be set to detonate either on impact or only after penetrating armor.[3] Fusing is controlled from a selector switch on the rifle.[1]

Long Range Stabilized round: An extreme-range fin-stabilized ball round with an effective range of 3,800 meters.[1]

M250 round: The M250 10×28mm Caseless round from the M56 Smartgun can also be used in the M42A without modification, although the effective range is reduced well below 2,000 meters.[1]

Behind the Scenes[]

The M42A was designed by Captain Ian Mitchell, a member of the British Army Reserves (then known as the Territorial Army).[4] Mitchell had previously conducted extensive research into snipers and sniping for a 1994 conference at the Royal Military College of Science (RMCS), for which he wrote a paper entitled Sniping and C3I.[5] During the conference, he was approached by Lee Brimmicombe-Wood (whom Mitchell had previously met at Alien Convention '93) and asked if he would design an appropriate sniper weapon for the USCM to feature in his upcoming book Aliens: Colonial Marines Technical Manual. Mitchell agreed and in fact completed rough sketches for the weapon even as the conference was ongoing.[5]

Recalling how many of the weapons created for Aliens (props of which he had seen at Alien Convention '93) were based on real-world weaponry, Mitchell based the sniper rifle on the German-made Walther WA 2000.[5] The weapon's name, meanwhile, was inspired by the M24 Sniper Weapon System used by the United States Army. According to Mitchell, "For designation I looked at the Pulse Rifle — the M41 and remembered the great M14 rifle. If M14 becomes M41 in the Aliens universe then M24 should become M42."[5] "Scope Rifle", meanwhile, was influenced by the fact sniper rifles in American service are sometimes referred to as "Bolt Rifles" due to their bolt-action mechanism.

A similarly-named USCM sniper rifle called the M42C Scoped Rifle later appeared in the 2010 video game Aliens vs. Predator, a fact that Mitchell noted.

"Over the last couple of weeks it has been fun using the M42C in the computer game Aliens Versus Predator [sic]. It would be great to see a real world version of the M42A!"
―Ian Mitchell on the M42C[5]