Originally Posted by cynicrit
OK, I've gotten some excellent input to my original question about burning out a barrel. I have a couple more questions. Does this erosion happen more in one area or the other, or does it occur pretty much throughout the bore at the same rate? Is there some objective way to measure how much erosion has taken place? I hear people say "That barrel is shot out." "How do you know" "Well I cleaned it, but my groups have still opened up an inch from what they used to be." That could be a lot of things, including (as I found out) an ineffective bore solvent.
Most of the time the loss in accuracy is very slow and not that much.
It sounds like you may have another issue Like bedding, a bad batch of powder (Not the same as the last you used or worked up with,
The best way I know to measure the throat erosion (Normally the first thing to go) Is to measure the Cartridge overall length while the chamber is new and keep the measurement,then if accuracy fall off check it again and you can see the difference.
If you know someone that has a bore scope you can look at the throat and lead to also see how much erosion you have (Don't be shocked if you look at it with a bore scope because it looks much worse than with a simple bore light).
I recommend a through cleaning, Bed and float the action and barrel then shoot 3 shot groups cleaning between each group and changing powder and primers on each group. This may rule out
any barrel problem.
The rest of the barrel last a lot longer than the throat. but look at the crown to see if it needs freshening up.
Hope this helps
J E CUSTOM