I've shot a couple w/ bayonet lug ground off, and several w/o bayonet attached.
Shot fine for me.
Last one I shot the previous owner had ground off the lug, a very nice job, I don't know if he had adjusted the sights or not, but it was spot-on and the last 4 shots into the bullseye at 50 yards.
If I was at Stalingrad, I'd keep the bayonet. But I'm not at Stalingrad.