By: A. Rifleman
And a dirty rifle can be a nightmare of malfunctions. All too often, during Sunday, I see shooters with semi-auto .22s suffer malfunctions that cost them points – and worse, break their concentration and raise frustration. The most common type is a failure to fire followed by a failure to extract as the unfired round sticks in the chamber.
The most common cause of this frustrating malfunction is a dirty chamber; in particular, a ring of hardened carbon just ahead of the case mouth.
The carbon ring prevents the cartridge from seating all the way in, leaving the case rim a little bit away from the breech face. This is the core of the problem.
In the Ruger 10/22, spring pressure on the bolt may be insufficient to fully close the bolt into battery, which prevents the hammer from fully striking the rear of the firing pin. This is because the firing pin is in the top of the bolt, and the hammer catches on the bottom rear edge of the bolt. The design of this is intentional, to prevent out-of-battery discharges. If the bolt does go into battery, the firing pin may merely push the cartridge forward or bend rather than crush the rim. Often one then has to dig the cartridge out of the chamber with a knife, and one can feel the resistance as the bullet was stuck in the fouling.
In the Marlin 795, the bolt also may not go fully into battery. But since the firing pin is in the bottom of the bolt, the hammer is able to hit solidly on the firing pin to cause an out-of-battery discharge rather than a failure to fire. In an OOB discharge, the unsupported portion of the brass case may blow out. An OOB discharge can damage the rifle or cause injury. The M&P15-22 also has a firing pin located low in the bolt and can suffer similar OOB discharges. Both rifles can also suffer fail-to-fire conditions as described above.
All .22LR rifles get dirty with buildups of soot, primer material and lead dust in the chamber and bore. Semi-auto rifles get especially dirty because of the blow-back action. As the bolt opens, hot, dirty gas blows back into the receiver, getting on the bolt face and into the bolt’s extractor and firing pin channels. The open bolt also allows the gas in the chamber to cool quickly which condenses the soot and vaporized lead into a solid buildup in the chamber.
A factory-stock .22LR rifle is designed with a looser chamber (to SAAMI “Sporting” specification) to eat almost any ammo reliably for hundreds or thousands of rounds, even under “deferred maintenance” conditions. But if you have an aftermarket barrel or your factory barrel has been tuned up, meticulous cleanliness is the key to reliability. If you shoot very dirty ammo such as Remington’s bulk brands, Armscor or Aguila, you will also need to clean more often.
Now the question is, what’s the best way to clean your semi-auto .22 rifle? There are many ways to clean the rifle. Some work better than others, and a few can cause premature wear of the barrel, but the best examples come from competitive shooters who demand the highest accuracy and reliability from their equipment. They typically clean their rifles to as-new condition after each shooting session. Here’s what I do on my rifles (10/22s and Marlins in semiauto, and a CZ 452 boltie.)
First I remove the bolt and clean out the inside of the receiver with solvent. I want to clean the receiver first so I don’t introduce dirt into the bore in the following steps. Spray solvent, or wipe a wet patch, over the area to be cleaned and let it sit for a minute for the chemicals to do their job. Then use a Q-Tip or a patch to clean the open areas. In the tight corners, I place a patch over the area and push it into the corner and scrub using the point of a small kebab stick. These sticks work great because of their sharp points and wood material which cannot damage anything in the rifle as well as their disposably low cost.
Then I use solvent and a chamber brush to clean the chamber. An excellent chamber brush is the Gunsmither Tools Brush n’Mop. I also use my homemade chamber brush, made from a .243 caliber brass-core brush (either Dewey or Pro-Shot) bent at a 90-degree angle. I never put steel-core brushes, or any steel tools, into the bore. You need an appropriate solvent to get that carbon ring out of the chamber. A dry brush will not do the job. Also, a fast-drying solvent, such as Break-Free Powder Blast or Birchwood Casey Gun Scrubber, is not as good as one that stays liquid longer. My favorite solvents are Slip 2000 Carbon Killer, and Bore Tech C4 Carbon Remover. I have used Ballistol and Hoppes #9, but both seem to be weak at dissolving the carbon. (Note that just as with discussions about the best motor oil, one can get into a really entertaining argument about which solvents and which tools are best.) Spray that solvent into the chamber and let it sit for a minute or two before brushing.
My method is this: spray solvent in the chamber and let it sit while I clean the bolt. Then with the chamber brush wet with solvent, I insert the brush, rotate it back and forth to scrub, while slowly pulling the brush out. The rotation both scrubs and allows the bristles to change direction so you can back the brush out. I’ll do at least three passes with the brush. Then I pull a dry patch on a Patchworm from the muzzle (the plastic and cotton of a Patchworm will not harm the crown and I don’t want to push that crud all the way through the bore) and then another. Then I do the solvent/brush/patch sequence again.
When the last dry patch comes out clean, I test by inserting a round with the muzzle down. In an unmodified OEM barrel, gravity should cause the case rim to fully seat against the breech, and it should be easy and smooth to remove the case by hand. If you have a match or target chamber (slightly shorter than the Sporting chamber), you may have to press the bullet in lightly to seat it, as the rifling may slightly engrave the bullet. But it should be easy to seat the case rim firmly against the breech.
Then I clean the bore. In the shop I use a one-piece cleaning rod, a spear-tip patch jag, and a brass-core bronze brush. Steel-core brushes can scratch the bore and damage the rifling. The multi-piece aluminum rods that come with cheap cleaning kits are too flexible – they can bend in the bore and scrape, and the sharp edges of the section joints can damage the edges of the rifling. Also, bare aluminum oxidizes quickly, creating a layer of aluminum oxide on the surface – the grit in wet-dry sandpaper is aluminum oxide, not something I want in my rifle. Polished stainless-steel, brass, and coated steel rods work well. My favorite rods are the new carbon-fiber rods available from a couple of makers as they are strong, stiff and non-invasive to the steel. I also use the Patchworm, a pull-through system made of plastic which cleans very effectively and is totally non-invasive.
I no longer use the Boresnake or its similar competitors. I find that the cloth is too coarse to clean the rifling grooves, although it does a decent job on the lands, and it doesn’t do the chamber very well either. The grooves are where the lead and carbon seem to build up the most in the bore.
If you have a Smith M&P15-22 or a Ruger Takedown model, you can clean with a rod from the breech to the muzzle, which is the preferred method used by bolt-action shooters. Some 10/22 owners use a special jig to drill a hole in the back of their receiver so that a rod can be used from the breech. But this is not possible in the Marlin or Remington semi-autos. If you need to use a rod from the muzzle, be sure to use a muzzle protector (made of plastic or brass) so you don’t damage the muzzle crown with your cleaning rod.
Finally, I run a patch damp with Froglube or Hornady One-Shot down the bore, on the barrel’s outside surface, and on all steel parts of the rifle for rust protection. Both products are proven to protect extremely well.
Normally I clean my rifles thoroughly after every 200 rounds or so. In a match, I’ll do it every 100 rounds. At an Appleseed, I do a complete cleaning after each day of shooting and on the match-chambered rifles, at lunch. The methods described above work for me. Your mileage may vary. However you do it, make sure your rifle is clean at the start of each shooting day. Your scores and your temper will both be better for it.