Smart Advice on Protecting Barrel Crowns When Bore Cleaning
We talked with the experts at Bartlein Barrels. They confirmed that they have seen many, many more barrels harmed by crown damage caused by improper cleaning than by anything else. If you use a bronze brush, Bartlein recommends that you REMOVE the BRUSH after it passes through the muzzle. This is because the bristles take a set (pointing to the breech) during the out-stroke. In other words the bristles angle back as you push towards the muzzle from the breech. If you drag the brush backwards at the muzzle, you force these bristles to reverse direction abruptly right as they cross the delicate crown. In time, that can damage the crown. NOTE: John Krieger of Krieger Barrels also advises his customers not to pull a bronze brush backwards across the crown.
Response to Skeptics
Whenever we’ve published similar advice, given by guys who are producing some of the most accurate barrels in the world, some readers get extremely angry. They say, “You’re crazy! I’ve was pullin’ triggers when you were still in diapers. I’ve got Hall of Fame points and I say there’s no way a phosphor bronze brush can ever do anything to steel. You’re full of it.” Well, these guys are entitled to their opinion. But here’s our response. Number one, we’re just telling you what the barrel-makers are telling US. Don’t kill the messenger. Number two, many of the guys who say bronze brushes can’t affect the crown are the same guys who feel they need to recrown their barrels every 400-500 rounds (Do we see a connection?). Third, if you don’t think a softer material can affect steel, look at the steel ferrules of a well-used fishing rod — there the steel is worn away by plastic. (With time, water will wear away granite.) Lastly, this Editor can tell you I’ve seen the damage myself, first-hand, using a magnifying glass on much-brushed benchrest barrels. Right at the muzzle, the top edge of the lands had sharp, jagged edges that looked like little shark’s teeth, or the edge of a serrated knife. By contrast, a new barrel will have a nice, smooth straight edge along the top of the lands at the muzzle.
Also Be Careful with Jags
Bartlein’s experts also told us to be careful about the jags you use. Dewey-style jags in particular can cause problems. These have a long shaft with multiple rings with diamond-pattern “teeth”. The teeth are designed to grip a patch. The problem is that the lower rings may be exposed below the patch fabric, so the teeth can grind directly on the rifling and/or crown. Bartlein says Dewey-style metal jags can damage a crown very quickly if any of the toothed rings are exposed, metal-on-metal. Tim North of Broughton barrels also advises against using the Dewey-style jags with toothed rings. Interestingly, Dewey uses the same type of diamond-shaped teeth on the bottom of its “Crocogator” primer pocket tool, so you know those knurled teeth can scrape.
