Cleaning Rimfire Barrels
Rimfire rifle barrels are different from centerfire barrels in that they require very little cleaning and essentially no break-in procedure. We have asked several of the top rimfire shooters and gunsmiths that use our barrels about their procedures and based on our own experience, have come up with our recommendation for cleaning.
In a match-grade stainless steel hand-lapped barrel, leading is an almost nonexistent problem. Powder fouling is minimal too. It is possible however to have an accumulation of fouling in the leade area in front of the chamber. A build up here is detrimental to top accuracy.
We suggest cleaning in the following manner. After approximately 100 rounds push a dry loose patch through the barrel from the breach end. This pushes out loose fouling. Then take a tighter dry patch and work it back and forth about 10 times in the leade area, pushing it out of the barrel at the muzzle end when finished.
Every 200-300 rounds a loose (worn out) 22 caliber bronze brush, wet with solvent, should be worked back and forth in the leade area with short strokes and withdrawn from the chamber end. If there is any evidence of lead in the barrel then brushing the full length of the barrel with solvent is suggested.
Match quality bullets have a wax coating on them that aids accuracy. It may take 10-50 shots to “lay” a good coating of it down in the barrel and using solvents will only remove this desirable wax coating.
Users of the 10/22-type semi-auto barrels may have to remove the accumulated powder fouling buildup that forms on the breach end of the barrel. Extraction problems may result eventually unless solvent is used on this type of fouling.
The 22 WMR and 17 HMR cartridges are rimfires but they fire a jacketed bullet and therefore centerfire cleaning and break-in instructions apply.
The solvent we use and recommend for our barrels is Butch’s Bore Shine.