There is really no reason to get a sore shoulder on the range. Use a PAST recoil pad or place some towels between your shoulder and the gun. You don't want to develop a flinch absorbing heavy recoil while trying to sight your gun in at the range.

I use the fiber optic TruGlo sights on my Mossberg. Please note that, at least in my case, they needed a lot of adjusting to get them centered - you can't just snap them on and be ready to go hunting.

You can use light loads to center the pattern on your gun (cheaper and less recoil), then shoot a turkey round to make sure.

Good luck

Mouthcaller