I haven't tried bird shot, but when I fired 00 buck or slugs from my pistol grip shotgun (Winchester 1300 12 gauge) without a front grip, it flew up out of my front hand. I'm a big, strong guy, but I couldn't hold onto the front.

A front pistol grip fixed that problem, and introduced a new one. Lock that front elbow while firing, or risk hitting yourself in the mouth with the back grip.