Left to right: M30 with pistol grip and stock and breaching standoff extended, M30 with pistol grip only and breaching standoff retracted, and M30 underbarrel fixed to Colt-Rocker M4A1.

The Rocker Arsenal M30 Commando Key is a Paternian straight-pull bolt-action shotgun adopted by the Paternian Army to supplant and replace the M100 pump-action shotgun. The M100, while a solid and reliable design, is relativley bulky for its intended role, and the Paternian Army felt that a new combat shotgun was necessary.

Entries from KRIEG, Carlton Arms, and Rocker came forth. The KRIEG entry, the Carlton entries, and one of the Rocker entries were magazine-fed select-fire shotguns. This was the only manually-operated weapon tested. In tests, the standalone variant suffered in range, power, controllability, and rate of fire compared to the automatic weapons, the Carlton Standard ACS seen as the winner.

However, the weapon redeemed itself wholly in troop trials by the fact that unlike the others, it was designed to be mounted under a standard M16 rifle or M4 carbine using the same mounts as the M203 grenade launcher. This meant that where the other weapons forced the soldier to choose between a combat shotgun or an assualt rifle, the Commando Key allowed the soldier to carry both in a compact, managable package. Thus, while the other weapons received a mixed reception, the Commando Key was received enthusiastically. Thus, the Commando Key was adopted as the M30.