For automatic rifles, my opinion is that slowly heating up a new barrel from cold to hot is very important to prevent warping. Shoot strings of 5, 10, 15, 20, 25 and 30 shots with cooling periods in between strings. During the cooling periods cleaning can't hurt. The worst thing to do with a new barrel is to go out and fire a bunch of 30 round mags that causes a new barrel to get extremely hot can result in a permanently warped barrel. You only have one chance to break in a barrel. Why take a chance?