Far be it from me to out words in
@Supersubes mouth but I think what he is getting at is the barrel will be scaling probably 18-20” up from the throat. These can flake and imbed or otherwise damage the jacket, at which point you’ll start getting fliers at best and blowing up bullets at worst.
I have set back a 6.5x 284, as well as has one cut off and rechambered to 6.5x47L. (5” parallel) If you have enough parallel, setting back and changing to a smaller chambering may be possible. A 2 thread set back and rechamber to 6.5x284 may get you a couple hundred rounds, may not. Usually guys set back around 800 rounds to get to 1500. Guys have covered going bigger, 6.5-06 might get you the length you need with a standard bolt face. @Jwhuskey would be the resident expert here.
I’ve burned down 13 FagMag barrels and have another with 300 rounds in it now plus a barrel with 150 for another rifle. I’ve been shooting it since North Dakota Pat ( there’s a call back for some old timers) and 1100 rounds is the most I have ever gotten out of one accurately. I’d say you’re close to the end. If you’re shooting at 600y or in this may seem like a hammer to 1500 rounds. That same barrel and load will almost certainly be giving you unexplained fliers at 1k.
Long way around the barn to say you lay your money down and take your chances but it’s by no means a safe bet. Especially if you try to turn the heat up with an even faster chambering.
