This section on cleaning is not intended to be a detailed instruction, but rather to point out a few "do's and don'ts". Instructions furnished with bore cleaners, equipment, etc. should be followed unless they would conflict with these "do's and don'ts."
You should use a good quality straight cleaning rod with a freely rotating handle and a rod guide that fits both your receiver raceway and the rod snugly. How straight and how snug? The object is to make sure the rod cannot touch the bore. With service rifle barrels a good rod and guide set-up is especially important as all the cleaning must be done from the muzzle and even slight damage to the barrel crown is extremely detrimental to accuracy.
There are two basic types of bore cleaners -- chemical and abrasive. The chemical cleaners are usually a blend of various ingredients including oils and ammonia that attack the copper. The abrasive cleaners generally contain no chemicals and are an oil, wax, or grease base with an extremely fine abrasive such as chalk, clay, or gypsum. They clean by mechanically removing the fouling. Both are good, and we feel that neither will damage the bore when used properly.
So what is the proper way to use them? First, not all chemical cleaners are compatible with each other. Some, when used together at a certain temperature, can cause severe pitting of the barrel -- even stainless steel barrels. It is fine to use two different cleaners as long as you completely remove the first cleaner from the barrel before cleaning with the second. And, of course, never mix them in the same bottle.
Follow instructions on the bottle as far as soak time, etc. . . Always clean from the breech whenever possible, pushing the patch or swab up to the muzzle and then back without completely exiting the muzzle. If you exit the muzzle, the rod is going to touch the bore and be dragged back in across the crown followed by the patch or brush. Try to avoid dragging things in and out of the muzzle. It will eventually cause uneven wear of the crown. Accuracy will suffer and this can lead you to believe the barrel is shot out, when in fact, it still may have a lot of serviceable life left. A barrel with a worn or damaged crown can be re-crowned and accuracy will usually return.
The chemical cleaners may be the best way to clean service rifle barrels that must be cleaned from the muzzle -- i.e. M1 Garand, M14, etc. . .-- because this method avoids all the scrubbing necessary with the abrasive cleaners and the danger of damaging the crown. But again, as long as the rod doesn't touch the crown, abrasive cleaners should be fine.
Abrasive cleaners work very well. They do not damage the bore, they clean all types of fouling (copper powder, lead, plastic), and they have the added advantage of polishing the throat both in "break in" and later on when the throat begins to roughen again from the rounds fired. One national champion we know polishes the throats on his rifles every several hundred rounds or so with diamond paste to extend their accuracy life.
Again, as with the chemical cleaners, a good rod and rod guide is necessary. A jag with a patch wrapped around it works well. Apply the cleaner and begin scrubbing in short, rather fast strokes of about two to four inches in length. Concentrate most of the strokes in the throat area decreasing the number as you go toward the muzzle. Make a few full-length passes while avoiding exiting the muzzle completely, but do partially exit for about six strokes. You can avoid accidentally exiting by mounting the rifle in a vise or holder of some sort and blocking the rod at the muzzle with the wall or something to keep it from completely exiting.
This sheet is intended to touch on the critical areas of break-in and cleaning and is not intended as a complete, step-by-step guide or recommendation of any product.