The type-III SOCOM carbine originated as the replacement for the standard type-III model 2355 shipboard phaser rifle when it was introduced in 2365 in concert with the latest upgrade series. The weapon served in this capacity until 2370 when it was finally phased out in favor of the more powerful compression phaser rifles. The decision to begin phasing out these weapons early was made when it was discovered that the Romulans had stolen the design and were making copies in order to implicate the Federation in several uprisings beginning in 2367.
Dominion War reprieve[]
With the outbreak of the Dominion War, the Federation Council Armed Forces Committee recognized the need for a cheap and effective weapon that could be deployed in larger numbers than the newer rifles, and also serve as carbines for small craft, which do not have the facilities for a full armory. The former type III standard rifle was chosen as it was far simpler and lighter than the newer compression rifles, as well as there being a massive surplus of the weapons following their rapid withdrawal from active service.
Special operations[]
The weapon was soon adopted by Starfleet Marines and Starfleet Special Forces Command as a weapon of choice for covert operations, who preferred the weapon not only for its light weight but also integrated rail interface system, which allows for the attachment of various accessories such as light beacons, tricorders and photon grenade launchers. (Star Trek: New Order)