How hot do you let your barrels get before you give them a rest to cool down? I was reading a post on another forum about someone who was shooting a semi-automatic and he was shooting several magazines end to end at one time with a 17 shot auto. I can't feel the barrel on a semi auto due to the slide. With a revolver I can feel the barrel and after 3 cylinders full of what I shoot, it is really hot! How hot can a barrel get without hurting it? I know this is subjective but I don't want to hurt my guns from shooting them until they give up and fail. The barrel on a revolver is different than a barrel on a semi-auto since it is detached from the frame. But barrel steel is barrel steel and I don't want to ruin my semi-autos due to not being able to feel the heat in the barrel because the slide is covering it.