Who’s LG shoots under 3 in regularly?What is considered "shot out" varies among applications and people.
If a light gun (5-shot groups) LRBR barrel had been shooting under 3" at 1000 yds, and then opens up to 5"--and that is with me keeping up with tweaking the tune before each match, I consider that barrel shot out. It might be a candidate for a new chamber, but only because I have my own lathe.
Also, If one of my LRBR barrels gets past 800 rounds and is only a mediocre shooter, it comes off and scrapped. If it's a really good shooter I might rechamber it, since I can do that myself.
Now if a big game hunting barrel goes from 1" to 2" groups at 300 yds, I don't see an issue.