Carbine

A Carbine is a shorter, often lighter, version of a full-sized rifle. It may also refer to a light, gas-operated semi-automatic rifle "that is also generally shorter and less powerful than a full-size rifle".

United Nations Space Command

 * M6J/C Carbine - The UNSC carbine variant of the M6 series of firearms, used by the UNSC Army.
 * MA5K Carbine - A variant of the MA5B wielded by Spartan-III's in Halo: Ghosts of Onyx.
 * MA2B ICWS/Carbine - Successor to the MA1. Functionally similar to the the MA5B. Occasionally used by Special Forces operators.
 * Asymmetric Recoilless Carbine-920 - Compact-channel linear accelerator carbine, fires high-explosive rounds at extreme velocities.

Covenant Empire

 * Type-25 Carbine - A single-handed Covenant projectile weapon featured in Halo 3, commonly known as the Brute Spiker.
 * Type-33 Carbine - A one-handed Needler. Used in a similar fashion to the Assault Rifle.
 * Type-51 Carbine - A two-handed Covenant projectile weapon featured in Halo 2 and Halo 3, known as the Covenant Carbine.