LonghornAR,
I have been using the barrel break-in procedure the mattld linked you above. Essentially, it is a simple and rough outline of how Mike Rock breaks-in barrels and why. I’m sure you’ve heard Mike’s name dropped every now and then on the internet in association with barrel making – and rightly so. He is an extremely smart guy who has forgotten more about barrels than most will ever know. Like you, I have noticed that there are as many schools of thought about break-in procedures or no break in procedures, for that matter, than one can count. Personally, I tend to differ to individuals who have the experience and knowledge when I encounter a subject where I have a technical question.
I have been using the Smooth-Kote and BP-2000 products from Sentry Solutions for quite some time - 3 barrels that I still own. I have been very please with the results and longevity of the accuracy in those barrels. I have also been impressed with the ease of cleaning, lack of fouling, and copper deposits. I strongly recommend them and have no affiliation with their company. I do, however, have a strong affiliation with my wallet and don’t like having to pay for new barrels when accuracy drops off. If you do choose to use the Sentry Solutions products, the small bottle of Smooth-Kote goes a long way. The small bottle of BP-2000 dry lube gets eaten up pretty fast. I have also found uses for it other than barrel break-in, so I use considerably more often.
Again, the link that mattld sent you is a good outline, but unfortunately the posting that made its way to ar15.com in that link leaves out something that I think is very important. One key element that should be added, if you expect have an accurate setup that lasts: spend the money and buy a good hand-lapped barrel from the beginning.
Additionally, it has been my experience that using cleaning rods (or anything that passes through the barrel) made from a softer metal than the barrel material (aluminum, brass, bronze, etc.) with a bore guide will save your bore from being damaged more than anything else. And keep these items clean, too. No matter what barrel break-in procedure that you choose to use (or not use), it will not save your barrel from having your lands ground on by a sand-coated USGI steel cleaning rod.
I understand that there are many different opinions about barrel break-in and, there will undoubtedly be those who disagree with my opinion and practices. This is merely what has worked for me at the suggestion of others. I don't intend to offend anyone, just my two cents and the subject.
Mike Rock is currently turning a custom barrel for me. I plan to rehash his suggested moly treatment again with him when I go to pick it up. If there are any additional details, I will certainly post them.
BertR