USAMU Talks about Pull-Though Bore Snakes

Each Wednesday, the U.S. Army Marksmanship Unit publishes a reloading “how-to” article on the USAMU Facebook page. Today’s “Handloading Hump Day” post covers bore-cleaning, specifically the use of pull-through style bore snakes. Visit the USAMU Facebook page each Wednesday for helpful tips.

Today, we’ll shift from handloading to rifle bore cleaning and maintenance, with information courtesy of the USAMU’s Custom Firearms Shop. We recently had some inquiries about bore cleaning, and this seems a good opportunity to share. After all, even the best handloads won’t yield their full potential in a poorly-cleaned and maintained rifle.

1. BORE SNAKES: MIRACLE REPLACEMENT FOR THE CLEANING ROD?
The experiences of both our firearms test specialist and this writer have given no evidence that proper use of a clean bore-snake will damage a match barrel. Of course, one does not pull the bore-snake at an angle to the crown when removing it — pull it straight out, parallel to the bore’s direction, to prevent crown wear over time.

Bore-snakes are very useful for some applications (primarily a hasty, interim wipe-down). In [my] experience they cannot replace a thorough cleaning with a proper rod and brushes. While the experiment cited here involves rimfire, it may help illustrate. Several years ago, the writer used his new, personal Anschutz to investigate the bore-snake issue. It had been fired ~350 rds with match ammo and had had 3 typical rod/brush cleanings.

Next, starting with a clean bore, the writer fired 300 more rounds without cleaning in order to build up a “worst-case” fouling condition. Afterwards, the writer examined the bore with a Hawkeye bore scope. There was a uniform, grey film down the entire barrel, with some small, intermittent lead build-up at and just forward of the throat.

A new bore-snake was then wet with solvent and pulled through the bore. The Hawkeye revealed that the grey fouling was gone, and much of the visible fouling at the throat was reduced. However, nine more passes with the bore-snake, checking after each with the Hawkeye, revealed no further improvement in cleaning. The writer then cleaned with two wet patches, observed, then one stroke of a new, wet bronze brush, and one wet patch to clean out residue.

The Hawkeye showed a significant reduction in fouling at the throat; it was virtually gone. A second pass with a wet bronze brush and a wet patch removed the remaining fouling. Scrubbing the bore further, checking to see how much fouling was removed, revealed no significant improvement. The reason for this test was to learn what’s needed to get (and keep) this Anschutz clean with minimal cleaning rod use — and thus, minimal risk of bore damage/wear. Leaving fouling in the bore promotes corrosion over time.

Obviously, this applies to a nice, smooth rimfire match barrel, using good, well lubed ammo. It doesn’t apply directly to the use of copper-jacketed bullets, which leave a stubborn fouling all their own. However, it does suggest that while the bore-snake can be helpful and a useful field-expedient, to truly clean a rifle barrel one will still need a good quality rod, bronze brush and solvents. [Editor: Add a good-fitting cleaning rod bore guide

2. SO, WHAT ABOUT BORE SNAKES FOR BARREL BREAK-IN?
The goal of barrel break-in is to fire each shot through a clean barrel, preventing copper buildup and allowing the bullets their best chance at burnishing sharp edges. Thus, it seems this purpose would be best served by one’s usual rods, brushes and rod guides.