There is the right way, the wrong way, and the Marine Corps way. It is known.
it comes to gun cleaning, the Marine Corps way is designed to cause
damage. The goal to remove every molecule of carbon. If reaching that
goal removes steel in the process, it's just collateral damage. Steel
cleaning rods and a heavy handed application of force will put more wear
on the bore of a rifle than shooting thousands of rounds.
have no proof, but personal anecdotal data suggests that the worst case
scenario is when the rifle is refused by the armorer because it's not
clean enough late on a Friday afternoon. If the Marine wants to go on
liberty he has to get that rifle turned in. If carbon free, completely
dry, white glove clean is the requirement and that date with Suzy is the goal, that Marine is now a rifle cleaning machine.
see the wear at the muzzle and in the throat because that is where the
cleaning rod rubbed as it was being pushed ever so vigorously into the
barrel. A military rifle that has seen a lot of use will have a battered
crown, and the rifling will either be missing or barely visible in the
last 1/2 inch or so.
I had to be retrained in a more
rational cleaning process when I became a shooter as a civilian. You do
want it clean, but it's still good to remember you will be shooting it
again soon. Box O' Truth offers what he does when he cleans old mil-spec rifles. I may not do this exactly, but his way is probably better. At least you won't do any new damage to your old rifle.