Can a person perform load development while breaking in a new barrel? Will pressures change as the barrel is broken in? Thoughts and input appreciated. Thank you in advance.
I personally have never been a believer in barrel break-in, give the rifle a real good clean then go to the range. Always wary of getting it too hot but just shoot it, I don't target shoot though so target guy's may have other theories, only use the initial range session to get the zero set then go hunting.
Cheers,
Waldo
I never tried to do it before this year . I always just loaded up some ammo , or used store bought and shoot one and clean , shoot one and clean , to help smooth the barrel . about 2 months ago I bought a 7mm-08 . I needed to reduced the recoil a little . I made a few rounds each of different charges of powder . while we were shooting these I watched the trend of where each charge was impacting . I kind of thought 39.0 grains should be a good load , it was . the top 2 taped holes are the last 2 shots of shoot & clean . I then let Denise shoot 2 shots and I cleaned it , then she shot one more . these are the bottom 3 taped holes . now I had a barrel with one fouling shot through it to test what I thought would be good . I shot the top 3 shot group that is not taped . I'm sure not saying it works every time , but it did this time . Jim
The biggest factor for barrel breakin is the quality of the barrel. With normal factory barrels that are hammer forged, there is usually a need to "lap" in the barrel and smooth out the rough spots. There doesn't seem to be the same need to do this with premium barrels. I used to do the one and clean for the first 20 rounds with all barrels, but just shoot the barrel now and let it tell me when accuracy is falling off. A new barrel in a 6.5X47 has about 120 rounds through it now and it has been cleaned twice. I am still playing with bullet/powder/primer combinations, so this barrel is being broken in while doing the load work. Everyone will have their way that works, but I think more barrels and crowns are ruined by over cleaning than not cleaning enough.
I think there are too many assumptions when it comes to barrel break-in practices. For custom barrels, I would do what the barrel maker recommends. For factory barrels, I start with min-charge loads to sight in and work up from there, watching for any signs of accuracy trends. Once I see a charge, could be more than one, that shows potential, I load up more for another range session. I clean my barrel at this point for two reasons: because it hasn't been cleaned by me yet other than an initial wet/dry patch, and to see if the cleaning affects accuracy at all. Just by knowing if the barrel "likes" to be clean or fouled helps me with load development and break in at the same time. For one rifle, I did the shoot and clean after each shot for the first 10, then clean after every three for the next 30, etc. and I found no benefit to it other than taking a lot of time.
I also prefer aftermarket barrels, and my procedure is to first coat the barrel with Dyna Bore Coat the night before I go out. DBC makes cleaning a rifle barrel a snap. Literally 4 or 5 patches for a clean barrel. Here's a link:
If breaking in a factory barrel I would use the David Tubb bore lapping bullets, clean, and then go through the application process for DBC. DBC has to harden overnight, so this would take 2 range trips. Here's a link to the Tubb Final Finish product:
I would also note that many, many rifle barrels have not had any of this done to them! The US Marines sitting at Chosin Reservoir during the Korean conflict didn't have these luxuries, and last I checked the Marines are suitable riflemen.
I do load development while breaking in a new barrel. It is all relative and the best powder bullet combination will still be the same, just better groups when broken in.
I have not had "hundreds of rifles" but have had quite a few over the years. Never worried about barrel breakin with factory barrels. I run a patch or bore snake through every 5 for the 1st session or two and never shoot em with a hot barrel.