I do remember checking my brand new slug gun for zero. Used a bullseye target at 25 yards. I punched a hole so perfectly through the ten ring, I actually thought I had missed the entire target at first.

My first hunt with that slug gun and the front sight fell off.

Been my experience the gun is usually way more accurate than the shooter is. It takes a lot of practice before a shooter is good enough to start tweaking reloads.