Stubborn patch of barrel won't clean.

[BoydAllen]

Eddie,
Thank you very much for all of that information.

This last year, I have helped a friend get started in benchrest (6PPC, group), and he has done a good job. He does his own barreling, has a bore scope, and is 15 minutes from a range on private property. Since he has settled on LT 32 as his powder of choice, and we have come to the conclusion that to stay ahead of the carbon situation, that different cleaning is required than for 133, I told him how Boyer recommended dealing with the problem, back when he was shooting T powder, that had the same issue. Because my friend has learned to do some remedial bore lapping, he is well aware of the potential of fine abrasives as far as over polishing a bore's finish, and that that will eventually lead to copper fouling problems that will not go away. For this reason, he uses Iosso, on one of the softer nylon brushes, at the end of an agg. Any intermediate cleaning, the frequency of which is determined by the fouling characteristics of a particular barrel does not involve the use of IOSSO. Because the tendency of a lapped barrel to pick up copper is closely related to velocity, and the hard carbon deposits are in the back of barrels, he avoids using IOSSO where it is not needed, short stroking the area where it is. I know that you probably are very familiar with all of this, but I thought that recounting it might be useful to some readers. No one can claim to have better credentials in the short range benchrest game than Mr. Boyer, and the method that I told my friend about, that he currently uses with good results, is straight from Tony (more conservatively applied), from back when he was shooting a powder that while very good, that had the same issue. As I have said before, with 133, this has never been necessary.

Something off the subject that you may find interesting, form a gunsmith's perspective, is that my friend has learned to survey the interior dimensions of barrels using cast, pure lead laps, to a high degree of accuracy. This has allowed him to catch barrel defects, before chambering, and to diagnose accuracy problems that would otherwise have remained mysterious. He has a long history as a race engine builder, and has a high degree of skill with tools and a good ability to solve mechanical problems. Currently his LV and HV rifles have new Bartlein and Krieger barrels, and he is well pleased with both.

 

[Alex Wheeler]

http://www.6mmbr.com/borebrushing.html
More mixed opinions to confuse you more. ;D

 

[JRS]

"If you do this, you're on your own. You wreck
/damage the chamber/barrel, you have to take responsibility for what you're doing to it"

Later, Frank
Bartlein Barrels

I'll put my trust in Frank and Bartlein Barrels, long before banking on an engine builder :

Something of importance to add: back in the day, while living in Phoenix, my 6PPC was going south after about 500 rounds. Gary O was working with Lester Bruno at the time. I gave him my gun to check it out. At the time, I was using the IOSSO and JB method used by many. After receiving the diagnosis from Gary, my chamber went from the original .262 to .268, and it was no longer centered. Walt Berger had but one thing to say to me. " I told you what will happen".

 

[BoydAllen]

I would have loved to see your cleaning method in action. That is precisely why barrel makers publish the disclaimers that they do.

Back in the day, a friend wiped out the throat of a new barrel with an abrasive cleaner, at a single big match, using it vigorously and often with one of the bore guides that were pretty much in universal use at the time. After he realized what had happened, first he tried to get a manufacturer to make what he wanted. Failing that he designed one of his own, that is sort of a cross between a Neil Jones guide and what later came out from TK Nollan. I have a couple of them, and use them with care. Equipment matters. Technique matters, and having the use of, or owning a bore scope, so that you can determine when you have a problem that patches, solvent and bronze brushes will not fix, and how many strokes, in what area of the barrel are needed to deal with it are as well. Abrasive cleaners are like sharp knives, handy when needed, and to be used with care. In the last few years, when friends have gotten their first top grade benchrest rifles, I have advised them to immediately buy the best bore guide available, even though it costs more than three times what more common ones do, and to wipe off their rods every time that they are removed from a barrel. Speedy one wrote that if a guide is big enough at the back to allow a brush to pass, it isn't doing much more than keep solvent out of your action.

 

[Alex Wheeler]

Well said Boyd.
JRS, we all know abrasives are designed to remove material. When used properly in a barrel they will do no harm, and are the only way I know of to remove the carbon a brush and solvent will not remove. I shoot rl15, its very dirty, I use iosso every 100 rounds or so to keep the carbon at bay, verified with a borescope. I have seen barrels quit shooting due to carbon build-up. The only reason I keep arguing with you is I don't want a new shooter to believe you and end up being afraid to use an abrasive cleaner. If your skill level prevents you from being able to properly use an abrasive then may be its best not to, but most can handle it.

You expect me to believe you opened your neck diameter .006" with some JB? Nice try. You still have not told us how you would get that part of the barrel clean that solvent and brushes wont clean. I'll be done now.
Alex

 

[Old Navy]

http://www.6mmbr.com/borebrushing.html
More mixed opinions to confuse you more. ;D

Now that was no help. Later! Frank

 

[JRS]

If you want to doubt what Gary O'Cock stated alex, that is entirely up to you. When you consider the fact that reamers are held to certain tolerances, the .262 could actually be as much as .264. I haven't told you what I do because you haven't asked Alex. I do however use N20 for more than making power How did we clean the throat area in the past Alex? Now we have people advocating the use of a drill to spin the brush and many are doing just that. Watch some of the big name, long time competitors scrub their barrels.