I am breaking in my new Kimber 8400 Montana in 30-06 tomorrow. Unless I get some other suggestions or pointed in a different direction I will do the following.
Using 150gr factory ammunition (Winchester & Federals) I will take these steps.
1. I will shoot one round and clean with bore slovent (foam solvent waiting 30min. for solvent to break down the copper) until the copper does not show up on any patch before I move one to fire the next round for five rounds.
2. I will then shoot one group of three then clean as stated above and do this for 5 consectittive groups (15 rounds) or until no more copper shows up on a second patch while cleaning the barrel after a three round group). if at anytime during this process no copper shows up on a second patch after a three round group I will consider the barrel broke-in.
3. I will continue the same proceedure of cleaning the barrel but for the next 20 rounds will shoot 4 five shot groups. (at anytime a second patch after a five shot group does not show copper I wii consider the barrel broke in).