I've used .357 mag, w/6" barrel on boar weighing up to 250 with no problems. I'd rather not increase the recoil or the noise with anything larger. I've already had my bell rang hunting with a .357. Fortunately all was okay with my hearing after about a week. The ear doc said I was lucky not to have a permanent hearing damage. Never had a problem with the report from long arms, but pistol hunting was harder on the ears than expected. Now I bring along ear protection when pistol hunting and slip them on just prior to pulling the trigger. I know that can result in blowing a shot, but now it's a priority for me to protect my hearing before taking game. The following year I took another hog with the ear protectors, and fortunately I was able to get them on just before taking the shot without spooking the animal or changing the situation.