On a shotgun is there a certain measurement from the tail of the stock to the trigger that is kind of a rule? Or can you do anything that feels comfortable? The reason I ask is I was shooting skeet the other day and someone mentioned that it looked like I was up on the gun pretty tight that measurement was 14 inches, my shotgun will take spacers so I added another inch and a half to it to make it 15 1/2 and it feels much more comfortable but I didn’t know if I’m going into uncharted territory. Thanks for the help.