US Patent 10260829 Shotgun conversion method and apparatus

Disclosed herein are modifications to a firearm of the assault (tactical) weapon style which allow those familiar with these sorts of rifles, especially the AR-15, and AR-15 variant rifles, to rapidly gain comfort and precision with a shotgun of the semi-automatic or potentially automatic feed mechanism in that the disclosed shotgun is externally the same and substantially identical externally to the assault weapon to which they are already familiar. In particular, the disclosed shotgun has a receiver, pistol style grip, hand guard, magazine receiver, and stock adapter which is substantially identical to an AR-15 or AAR-15 variant rifle to which they are already accustomed.