I've shot a pistol-grip-only shotgun once; it really was nasty, and my accuracy was rather less than stellar at distances greater than about 5 yards. The presence of a butt stock really helps with control of a shotgun while firing. Put a PG and a butt stock together, such as in the Knoxx Spec-Ops unit - now you're talking
This here is good advice
Ive shot my Mossy with only a PG and it only took a few shots to tell me this is not the way to do it even tho it looks cool in the movies. Even with "low recoil LE buck shot" it is not fun for me.
