Tweetthink about it for a second. Let's just say you have a national or prof.BB right? Don't you think that after 8-10-12 years of shooting in the ass the muscle fiber might not be tore up ? Everyone should alternate whether your a newbie or not. I alternate to ALL of the places I can shoot just so that I give all of spots a rest. I start with my ass, then go to bi's, tri's delts, traps, lats, calves and quads. I've luck enough to never have shot into or through a vein(knock on wood)