RE: 20 guage mossberg
I do the same thing with my son. He never shot buck shot until he shot at a deer. He shoots bird shot and the range and he has shot 1 shell of turkey shot. His new 870 with a Gobblin Thunder Choke tube from Kick's Industrys shoots a great pattern. The range only has 25 yards and 50 yards so when we shoot at the range we set up for 25 yards and there it is very impressive. At my uncles sand pit I set up at 35 yards and it still threw a very nice pattern. I think I am going to use 35 yards as his limit. Good luck