Re: what is the correct way to shoot a new barrel in?
My experience with new barrels on new factory rifle has not been consistent, except on one point. When they arrive newly in the box, the bores need cleaning. There's usually a crapload of industrial junk and dust, etc. living in there. While I may or may not be inclined to run abrasives down the tube, I am danged certain I don't want the first bullet driving that junk into the walls of the bore. Don't be surprised if you find copper, they do get proof fired, and subsequent cleaning? Your guess is as good as mine on that.
Factory barrels generally lack the final lapping process that a premium replacement barrel would get. The resulting inherent bore roughness contributes to initial copper/lead fouling.
Whether one firelaps or otherwise performs a bore initialization process, normal firing wear will eventually remove the bulk of this. The primary difference is about how much scrutiny this process receives. In other words, is the initialization under control or not?
Honestly, the more important part of initialization is about using the copper solvent as an indicator of the bore's copper fouling rate. The more valuable data relates to how fast the copper is accumulating, so some conscious thought can be given to whether and how often it may need to be removed.
For me, break-in consists of cleaning every few rounds, and using the patches as an indicator of when the initial high copper fouling rate is actually beginning to fall off, and how fast that process continues.
If you try this with a premium pre-lapped barrel, it should become immediately obvious that copper is not an issue, and that cleaning isn't going to tell you much other than that the copper is going to be pretty hard to find threafter.
The factory barrel generally tells a different story. Bore roughness and significant copper fouling accumulation go hand in hand. This may or may not be an accuracy issue, and the same question applies to carbon fouling as well.
It is my personal belief that carbon fouling is simply an accumulation of the graphite that is usually present in propellent kernel coatings. I think it doesn't burn very much, gets left behind when the combustibles are consumed, and may have more benefits than problems associated with it.
I'll get back to this.
Factory bore roughness is pretty much a fact of life. Over time, firing will reduce this, and copper accumulation will be proportionally reduced.
Some may not find this acceptable, and choose to hasten the process with abrasives. I have and no longer do. I can provide no better reason for either stance. I have simply become lazy in my old age and am willing to tolerate the copper accumulation. Millions of other gun owners do exactly the same and it seems to be a relatively benign policy.
I don't strongly subscibe to the concept that lapping the bore with abrasives is a harmful process. In the first case, the premium barrel makers all do it themselves. Factory barrels don't get it, and premium barrels don't need it.
In the second case, I don't see abrasive bore wear as the primary killer of good barrels. I reserve that label for firechecking, and view the abrasive wear factor as coincidental.
About carbon(/graphite?) fouling; it's a dry lube. It has a definite effect on bore transit time, and anything that does that is going to affect a load's compatibility with basic barrel harmonics. How, don't ask me, but that it's a factor, I'm certain.
To my simple mind, it clouds the accuracy issue sufficiently enough that I think I'd have to be bonkers to further complicate matters by incorporating other dry bore lubes, like moly.
This is the point where some may think I need to definitively assert the real truth about barrel break-in. So I will.
The truth is that there is no truth. That jury is still out, and I have a healthy disbelief in the words of expert witnesses on the subject. Nobody gets it all right. Until a litmus process can be derived that pries fact from opinion, nobody will.
Sorry folks, but we're all each on our own in this one.
Greg
