A former Army Reserve Marksmanship Program Armorer delves into maintaining match grade AR-15s.

by Joe Carlos

The “Gun Writer’s Union” requires every firearms journalist to write an article on the subject of bore cleaning and they have found me procrastinating. Part of the reason that I haven’t jumped into the topic is because with every gun writer out there having previously penned an article on the topic I felt that there wasn’t much left for me to say. However, as I remember back over a decade of being the armorer for US Army Reserve Marksmanship Program I probably replaced as many barrels either because of neglect (causing pitting) or due to damage from improper cleaning as I replaced for being genuinely shot out.

There are two really good reasons to clean the bore of any firearm. It improves accuracy and putting away a gun with a dirty bore is courting the formation of rust which will cause pitting, thus ruining a valuable barrel. As a general rule, I would clean every time I fired the gun unless the round count was well below 20 and the gun was going to be fired a similar modest amount the following day. An example might be some hunting situations.

Some experts claim that bore fouling is not cumulative, claiming no difference in the amount of fouling present after firing only one round compared to firing 500. That has not been my experience. If a team member retired and turned his guns in dirty, I inherited the mess. It has taken me up to a day and a half of continuous work to get some of these badly neglected guns cleaned. I don’t claim that fouling gets so bad as to plug shut, but I do claim two shots foul more than one and 500 is worse. Severely fouled bores likely require abrasives such as J-B Non-Embedding Bore Cleaning Compound in addition to copper solvents. I don’t believe J-B itself harms barrels, but back and forth scrubbing will cause rod flex that wears at the lands. I have seen many barrels destroyed by this. Ask any gun barrel manufacturer and I’ll bet they’ll agree. Remember that the land sticks up only about the thickness of a sheet of paper above the groove. Despite being made of hard metal it can be worn down by the movement of the rod, even coated ones.

Read more in our January 2015 issue. Back issues are available.

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