I hope I don't rub anyone the wrong way, but I have heard differing advice from the late Gale McMillan on the subject of rifle break-in. His advice mirrored J&T on running apatch through the rifle to clear any metal that may be left over from manufacturing, but then his advice was totally different. He recommended that the rifle owner take it to the range and shoot no less than 200 rounds through it before it was cleaned. Then clean it as normal with a mild solvent and brass brush (hoppes #9 is perfect). Avoid ANYTHING with steel bristles, which means that you should only run brass and patches through your rifle. Electronic defouling is a good idea once in a while too. Overcleaning has been the death of more accurate barrels than undercleaning ever has... Keep that in mind and enjoy the rifle.
Gale McMillan wrote more or less the same instructions on a gun-site not too long before he passed away and I figure that he probably knows best. I have followed that advice so far and I am happy with the results.