100 light target 12 gauge rounds in very (very) quick succession out of a Mossberg 88 will do a number on you head. Shotgun whiplash like I've never felt.
I was shooting and reloading as fast as I could.
9x19mm Parabellum didn't hurt, but it did feel like I had no control over the round.
Of course, it was my first time shooting a pistol, after being a longtime rifle and shotgun freak, and the S&W Model 59 didn't fit my hand very well, anyway.