The worse barrel I have shot out, my factory 300rum barrel off Rem model 700, it opened the groups over 1MOA at about 1500 rounds, I continued to shoot it, at 2500 rounds it Was hard to keep the shots inside a 2-3 MOA area, I finally pulled the barrel at 3500 rounds and it was nasty..At 1700 rounds I ran it by my local smith and they put a scope down the barrel, it was showing heavy cracks covering most of the diameter out past 6 inches or so.. Amazingly it showed light cracking all the way out to the brake...It wasn't near the damage up at the chamber end, but it was way more then I expected..A couple years back I got a cheap bore scope and have been checking barrels reasonable often...a lot of good shooting rifles are pretty heavily cracked up inside....
This is my AR barrel, as made by Larue...before firing, this is the gas port..
Attached FileThis is a bartlein barrel chambered in 300rum with about 1200 rounds thru it, still shoots sub MOA,but not as tight as it was when new..
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