My gun handles both...I prefer the bigger shell, if only for some added piece of mind... an additonal 1/4 oz of shot...not to mention the terrific patterns. My only beef with the 3 1/2'' load is so many guys I hear claiming they are comfortable shooting sixty yards and beyond. I've seen and shot alot of turkey guns and I have to tell you that I have YET to see a gun that would make me comfortable shooting at turkeys routinely at any distance past 50 yds. The introduction of the hevi shot family of loads has only fueled that crowd. For the record, I shoot copper plated #5...3 1/2" Win High Velocities. Kill them just as dead as anything else out there....no need to spend $50 for ten rounds. The name of the game is get 'em close. If you aren't good enough to close the deal, than accept that and work to get better. Don't rely on a super cannon to reach out there and cripple turkeys farther than you should be shooting them. I know several old timers that use to use .410's ......They also shot them at less than 20 yds, with nothing more than a "high brass" load of sixes or 7 1/2 shot....wearing denim coveralls with no facemask. You figure it out. Does your super camo and mini cannon, real taxidermed decoys, and hevi shot compensate for good ol' woodsmanship, knowing your gun intimately, and calling ability?