Re: What does "shot out barrel" mean?
Head space doesnt errode. The throat errodes the most and the fastest. You can set the barrel back a turn after it is cooked out IF the rest of the barrel is good. Sometimes several inches of riflings are degraded also. Most will agree that a barrel is "shot out" when it will no longer hold a resonable degree of accuracy. A resonable degree of accuracy will meen different things to different shooters. When a barrel starts shooting poorly, often times setting it back an inch or two will help, however if it took 800 rounds to loose accuracy you will likely NOT get another 800 accurate shots. It will likely be MUCH less. IMHO, when it is shot out, it is better to get a new barrel.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.