An older design of the Pulse Rifle commonly used by Colonial Marines. Uses 10x24mm caseless ammunition. Holds 95 rifle rounds per magazine. Slightly less accurate than the standard MK2 but fires in 4 round bursts instead of 3. It's also less modular than the MK2 but makes up for it in its high capacity magazines. Armour piercing magazines are also available for the MK1 and benefit from the substantially higher capacity magazines. The MK1 cannot use MK2 magazines in spite of them being similar.
Four rifles can be found in the command armory on the Almayer and they're available from requsitions where they're dispensed from their Armament Vendors. It is also one of the possible rifles for the Freelancer Mercenaries.