Felt concussion on a short barrel can be pretty heinous. On my 11.5", to me as the shooter, it feels no different than a 14.5" carbine. the 7.5" is a complertely different story. I started it with a standard A2, just to shoot it, and it damn near rattled my teeth - the concussion was BAD. I decided to not dick around with a bunch of different devices, and just put the KX3 (pig) on there right away. I feel no concussion now - just like shooting any of the other ones, now. The biggest advantage - people next to me don't get blasted out. <thumbsup> Mike has a shorty, too - I think it's a 7.5". I don't know what kind of muzzle device he has, but that thing was painfull to shoot beside. :o On a 10.5", you are right at that length where it might not bother you too bad, and it might not be very bad when beside it. There's ONE way to determine that, too... Have someone else shoot it, and you stand beside it. Once you do that, itll be pretty clear which direction you need to go. NOTE: I'm not talking about getting directly beside the end of the barrel. Keep yourself about 5 to 8 feet to the side... about the distance to the next shooting table at a range...