As a general rule neither the 1 oz 16 short magnum nor the 1 oz 3" 20mag is loaded to as high a velocity as the 3 3/4-1 12ga load thus can be shot out of a bit lighter gun. I have shot a few 3" 20's from a 6 lb gun. You definitely knew it went off & would certainly not desire to shoot a round of clays with it, but under hunting conditions with thick clothes & not a bunch of shots fired in rapid order it wasn't bad. Have also shot a handload oif 1oz from a 16 of similar weight @ a lowered velocity & it was even milder. Shooting steel of course you have a lighter charge weight with higher velocity. Space in the shell is really the limiting factor for either a 16 or 3" 20 when it comes to waterfowling. They were both adequate for most of it when Lead was still legal. Non-Tox was their downfall as far as waterfowling goes.
