In all fairness, Mike Rock is not the only knowledgeable person who thinks that barrel break-in is not all that it is cracked up to be.
This is what Gale McMillan had to say about the subject:
As a barrel maker I have looked in thousands of new and used barrels
with a bore scope and I will tell you that if every one followed the
prescribed break in method A very large number would do more harm than
help. The reason you hear of the help in accuracy is because if you
chamber barrel with a reamer that has a dull throater instead of cutting
clean sharp rifling it smears a burr up on the down wind side of the
rifling. It takes from 1 to 2 hundred rounds to burn this bur out and
the rifle to settle down and shoot its best. Any one who chambers rifle
barrels has tolerances on how dull to let the reamer get and factories
let them go longer than any competent smithe would. Another tidbit to
consider, Take a 300Win Mag. that has a life expectancy of 1000 rounds.
Use 10% of it up with your break in procedure for ever 10 barrels the
barrel maker makes he has to make one more just to take care of the
break in. no wonder barrel makers like to see this. Now when you flame
me on this please include what you think is happening to the inside of
your barrel during the break in that is helping you.
NBSRA IBS,FCSA and NRA Life Member
As for me; I take the time to complete a barrel break-in procedure on all of my new barrels. Not because I really know what it's doing but because I feel that it CAN help and it is unlikely to do anything harmful except to shorten my throat life by 50 rounds.
Hey - I put high quality motor oil in my 4X4 every 3,000 miles but does it really help ?????????