Frog, Cat, Pete and Fellow Newbies
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To follow up on Pete's mention of what I call "glazing", which most often is mistaken for "leading, loss of accuracy is the same result. I've inspected the throat area of many rifles that have "gone sour" with a 10x borescope, more times than not the throat area of the bore has a build up of a hard substance, like that found on a case neck that has been fired many times without wiping off the black residue from the cartridge neck. If allowed to accumulate on the case neck about the only way to remove it is with steel wool. This same condition occurs in the throat area of the bore and can easily be felt by the increasing force required to breechseat each bullet as more shots are fired, this seating force is most easily felt when a mechanical bullet seater is used. I beleive this "glazing" condition occurs most frequently when ball powders than with powders such as 4227 or 4759. Some primers also seem to contribute more to this condition than others as does humidity to some extent. Breechseating the next bullet to be shot as soon as possible after firing the previous one seems to reduce the occurance of "glazing".
For many years it has been my habit of cleaning my barrel at regular intervals to maintain best accuracy, build up
of "glazing" can lead to "leading". "Glazing" is best removed from the throat by cleaning with JB Bore Paste applied to a tight fitting cleaning patch. The affected area of the throat can easily be detected as the patch will seem to tug on the cleaning rod as it passes through this area. Clean by always having the patch return to the throat, as pass or two all the way to the muzzle with more cleaning stroke towards the breech, do not just work in the throat area alone, this glazing can occur the full length of the bore, but usually the most "glazing" will occur in the first 4 to 6 inches from the chamber. When the tug on the patch is no longer felt, clean the bore with powder solvent and dry patch.
When "glazing" starts to occur a gradually loss of accuracy will be seen by gradual increase in group size. Cleaning every 20 -25 shots does much to eliminate the problem, I have several rifles that have over 40K shots through them that have been carefully cleaned in this way with no loss of accuracy. I'm sure many shooters have had their rifles seem to go "sour" and clean for "leading" only to find none, what they have done without knowing it is find glazing. This regular cleaning will not eliminate any shooters inability to read conditions however.
Brent- Your reading as I'm taking breaks from writing. To answer your question if "glazing" occurs with BP as well as smokeless, yes and most likely more so. However, not being a BP shooter I would think the same would be true for breechseated bullets being seated as soon as possible after firing the previous shot as possible while the fouling is soft. I will defer to Pete for his opinion.
Frog - Sorry I didn't make it to the NRA Show last weekend, I was really looking forward to meeting all you fellas. Sorry I missed Max Goodwin too. Max is the father of single shot national matches, it was through his efforts that convinced Bill Coors into sponsoring the First Coors National Schuetzenfest in 1982, single shot shooting has come a long way since those days on a national scale. I WILL be at the EG match in May, am looking forward to finally meeting the "new oldtimers".
Regards,
Barry