Ok stupid question then fellas? I know the whole debate about barrel break in myth or legend. DD says all good and after bench resting my new M-4 V11 with a wicked tight group I believe them. Now on bigger / precision rifles such as on my Armalite AR-10 Super SASS and my previous DPMS LR-308 both companies gave explicit instructions in the owners manual on how to do so and that they strongly recommend it. Ok so, if I understand correctly the whole point of barrel break in is to 1. become familiar with the rifle and work on fundamentals 2. to use the bullet to smooth out any minor imperfections in the rifling and you clean after X-Amount of shots to remove copper / minor metal fowling to basically hone the rifling. So once you did this and you have shot say 2,500 rounds before copper fowling degrades accuracy and you need to remove the copper build up, hasn't the barrel been, "broke in"?
Robo After removing all the copper build up you should see a tighter group and possibly a minor POI shift from a better grab on the bullet. My old Remy 700 would do that and I recommend Copper Ease in a white bottle blue screw on top.