I have read alot of different ways of doing break in on 50 BMG, I also have heard some say it is not needed, Any comments out there from people who haven't broke their barrel in? How many rounds thru it? How is your accuracy?
IIRC, you are an member of the F.C.S.A, so log in and do a search.
There is so much input and good advice that I would not even be a to condense it here.
I have been firing a shot and running several patches of Montana 50 BMG cleaner through my Steyr.
Also use an nylon brush. I gradually increase the number of shots between cleanings.
The Montana cleaner removes the copper, however, lotsa MONIA in there!!
Here is some barrel break in tips from Pac Nor, a quality barrel manufacturer:
"For best results, of course, it is necessary to 'season' it and use proper cleaning equipment. We like the Dewey coated rods, a good bore guide, copper/bronze brushes and cotton flannel patches, the appropriate size to keep that jag and rod in the middle of the bore. You will need a good bore solvent, like KG 3, Shooters Choice or CR-10 to loosen the fouling, followed by a scrubbing with Holland's Witches Brew or KG 2. After cleaning, nullify the solvents with rubbing alcohol and patch dry. Finish with Tetra Gun Oil, KG 4 or Holland's Bbl Break-in Fluid. Never shoot a dry bore as this will greatly promote copper fouling.
Shoot one, clean, for first ten rounds; shoot three, clean, for next thirty rounds; shoot five, clean, while working up load. Allow bbl to cool to the touch before testing a new load to avoid unnecessary throat erosion."