I have posted a few questions before about my Ruger Hawkeye 300 magnum. I was at first disappointed with my group size but took your advice of not detail cleaning the bore after every range trip and my groups have settled in to about 1 inch at 100 yards. I am using Hornady ammo and am very pleased with my rifle now. My new son-in-law and I went to the range today. 100 plus degrees in Arkansas, and put about 24 rounds through it in about 45 minutes. We were not purposely waiting for a cool off period between rounds and the barrel got very hot but the groups stayed very consistent , my last 3 shot group was my best of the day at right at 1 inch. I am very suprised that a lightweight hunting rifle with a stock barrel will stay this accurate in these conditions. I guess my question is : Am I hurting my barrel by not letting it cool off some? How hot is too hot? I probably will not repeat a session like this again (pretty hard on the shoulder too).