Very cool ! Never have had opportunity to handle or shoot one of those.
USSS had some Remington 870’s and 1100’s that were cut real short and had some mod on the 1100 that allowed it to function reliably with a pistol grip.
That and the addition of the duckbill device made those a real hallway clearing tool.....
Say "Remington 870" around here, and Marines salute in the direction of Ilion, NY.
A duckbill spreader would be nice. I was told, but could never verify, that firing a shotgun on a downward angle towards a wall would ricochet the shot down the hallway, creating a swirly cloud that filled the entire hallway.