Once your patches come out pretty clean, you will know you are done!
And then, once you shoot it, you will find even more dirt than you think you should from the number of shots you made.
We're not kidding about the amount of dirt those barrels hold. Shooting it after cleaning for the first time releases even more dirt!
Also, a good copper solvent would be a plus to use on the gun.
Finally, something else not mentioned. A lot of surplus M-N ammo (7.62 x 54R) is corrosive. Shoot some Windex with Ammonia down the barrel when cleaning it. Kills the corrosive element.
The Doc is out now, again.