We don't recommend any special break-in procedure, as your barrel has already been lapped and test-fired before you get it. If you want to do something, we suggest a very abbreviated process:
Single load and fire ten rounds, running a lightly oiled patch down the bore after each round, then;
Single load and fire ten rounds, running the lightly oiled patch down the bore after the third, seventh,and tenth rounds, and finally single load and fire ten rounds, running the lightly oiled patch after the fifth and tenth rounds.
All you're trying to do at that point if remove any loose materials that may be coming off the rounds, especially copper jacket material.
We have a simple policy on steel cased ammo: DON'T USE IT! For every success story, we hear far more tales of woe and distress.
We use a generic GI manual, but any of the manuals that you can access and/or download from the ARFCOM manuals and instructions section should work for you for general assembly, disassembly, and maintenance familiarization purposes
Thanks.
Steve/RRA