Ask the Community

No, the Mossberg 990 Aftershock 12 gauge semi-automatic shotgun is not designed to reliably cycle mini shells, according to Mossberg. While some pump-action shotguns can be modified or adapted to use them, semi-automatic shotguns like the 990 Aftershock generally require heavier loads to cycle the action. Here's why: Insufficient energy: Mini shells, typically 1 3/4" in length, produce less recoil energy than standard 2 3/4" or 3" shells. This reduced energy may not be sufficient to cycle the action of a semi-automatic shotgun, which relies on the force of the fired shell to cycle the bolt and eject the spent casing.

Hi John and welcome. Unfortunately, mini shells will not have sufficient power to reliably cycle the action. Cheers and stay safe!