"Standard issue USCM 9mm pistol comprised of a lightweight steel alloy."
M4A3 Service Pistol description (from Aliens: Colonial Marines)

The Armat M4A3 Service Pistol (also known simply as the Service Pistol) is an American-made semi-automatic, recoil operated, magazine-fed pistol chambered for 9mm ammunition. It was notably employed by the United States Colonial Marine Corps as their standard issue sidearm. The M4A3 is part of the M4 family of handguns and was succeeded by the upgraded M4A4.


The M4A3 is a 9mm automatic, recoil operated, magazine-fed handgun. Coming with a notch and post iron sight, the working mechanism is made of steel alloy with some high-strength plastic parts, while the outer casing is machined from lightweight alloys. The entire weapon, including a full 12-round magazine, weighs no more than 0.95 kg.[3] The M4A3 is largely ineffective at stopping most Xenomorphs and Yautja, making it somewhat of a last resort weapon, [4] but it can be overpowered with M901 Armor-Piercing Round[3] or the A27 High Velocity Round giving it more punch. The M4A3 can also be equipped with a A7 Sound Suppressor for stealth operations or cover ops or an Armat Laser Targeting System for more precision.[1]

Notable Users[]

The M4A3 was known to be the standard sidearm of the Colonial Marines soldiers,[1] medics and Synthetics[4] since the 2120s,[3] but in the 2170s the VP70MA6, only available to officer until then, began to slowly replace the outdated M4A3.[5] Weyland-Yutani also equipped some of its forces with the M4A3.[1] At can also be acquired by civilians, corporates, pilots, Colonial Marshals and Mercenaries.[6]

It was also most notably used in 2179 by Samwell Stone, Rick Levy[7], Corporal Winter and Private O'Neal.[1]

In 2183, the USCSS Montero crew owns a single M4A3 Pistol.[8] Crewmembers of USCSS Cronus Albert Johns[9] and Lori Clayton[10]

In 2184, all Sin Eaters squad members owns a M4A3 as their personal sidearm.[11] On Ariarcus, combat synthetic Jaell,[12], Weyland-Yutani executive Mallory Eckford[13], Colonial Marshals and Insurgents.[14] Many soldiers and officers of the USS Tamb'Itam were furnished with a M4A3.[15]

In 2189, Private Anderson can used two of these weapons (either individually or akimbo) during his struggle on LV-426, Odobenus Station and the USS Tyrargo.[16]


  • 9mm Ball: The M4's (as well as some of its variants) standard ammunition is a 126 grain 9mm ball rimless straight round. Although adequate against soft targets, this round has very poor armor penetration characteristics even at close range, leading to the introduction of the M901 round.[3]
  • M901: A new armor-piercing cartridge being introduced to replace the standard ammunition for the M4, the M901 consists of a subcaliber metal core encased in a high-impact resin bullet. Upon impact, the resin case breaks apart, allowing the core to penetrate the target's armor.[3]
  • A27: A modified variant of 9mm ball that allows the round to exit the barrel at a higher velocity, inflicting more damage should the bullet hit its target. However this comes at a cost of a higher recoil and a lower rate of fire.[1]


  • The M4A3 in Aliens: Colonial Marines used to have the following attachments: A7 Sound Suppressor, Laser Targeting System and A27 High Velocity Rounds.[2] This weapon is unlocked by default, as with the M41A Pulse Rifle MK2, M37A2 Pump Shotgun and M40 HEDP Grenade, this is barring DLC unlocked weapons.
  • Unlike many of the weapons in Aliens: Colonial Marines, the M4A3 was actually not created for the game, first appearing in the Colonial Marines Technical Manual and then going on to appear in the 1999 video games Aliens versus Predator (Gold Edition and Classic 2000 versions only) and 2003 Aliens versus Predator: Extinction.
  • The M4A3 is visually based on the Colt M1911.
    • In fact, concept art for Aliens: Colonial Marines reveals that the M4A3 seen in the game was originally going to be a somewhat antique Colt M1911.
  • In Aliens: Colonial Marines, "COLT AUTOMATIC CALIBUR 45" can be seen at the weapon's slide, further supporting the above statements.[17] However, the M4A3 actually uses 9mm (or atleast, A27) rounds mentioned in the description instead of .45 ACP and moreover, the manufacturer is Armat Battlefield Systems instead of Colt's Manufacturing Company. It is likely that the developers forget to rename the label to M4A3 after the weapon was renamed as such.
  • Next to the label, there is a fingerprint that can be seen on both sides of the slide and on the grip.
  • A M4A3 Service Pistol worth $200 in 2183.[18]