Keep It Clean for Accuracy
September 23, 2010
The Sweeney System explains how, when and why to clean the bore of your barrel.
First up, an application of bore solvent to loosen the easy stuff. The Bore Tech rod guide makes it easy to apply solvent, and also keeps the patch in line for the rod. After brushing and patches, apply the copper solvent.
I have been all over the map on cleaning the bore of my rifles. I have used plain old oil, solvents that will strip paint or your liver, abrasives, soap and water, surplus GI solvent and anything else you can mention except axle grease or barbecue sauce.
I have cleaned and I've not cleaned. And I've done a lot of shooting. For over two decades, my logged ammo consumption was between 20,000 and 35,000 rounds per year. Most of it was handgun and shotgun, but at least 10,000 rounds a year was with a rifle. And for almost two decades, I cleaned and repaired guns for a living.
My first centerfire rifle was a Lee-Enfield Mk 1 and the only ammo I could afford was surplus and corrosive. After every range session I took the action out of the stock and scrubbed the bore with hot soapy water. I also took a fistful of aspirin, as the surplus military British ammo thumped my 139-pound frame pretty hard.
My second rifle was a match-conditioned Garand and, thankfully by then, I could afford non-corrosive ammo for it. While I didn't give it a cleaning after every range session, it did receive regular scrubbings. The next few rifles were not so fortunate. A raft of Mausers, a pair of Lee-Enfield Mk IVs, a Springfield and a couple of AR-15's came into my hands, and all received next to nothing in the way of bore cleaning. They all shot as well as I needed them to, so other than an occasional patch to get the grunge out, I didn't bother cleaning their bores.
Then I bought a used Springfield M-1A. The owner sold it because "the bore was shot out" and he didn't want to bother re-barreling it. Being a gunsmith, the thought of screwing a new barrel in was not a big deal to me. I tried it in a few matches and sure enough, it shot poorly.
You need cleaning solvents to clean the bore, but not every one ever made. Find what works and what you are comfortable with, and use it correctly.
I had heard of a bore cleaning product that worked fast and thoroughly, so I figured I'd try it until the new barrel showed up. The first patch that came out reeked of ammonia (as it had going in) and fairly glowed green. A light went on over my head. I spent the next couple of weeks cleaning the bore until there was no trace of green on the patches. (The ammonia smell nearly killed what little sense of smell I then had.)
The accuracy improved greatly. Boldened by this, I then match-conditioned it using the AMTU specs as a guide. The rifle proceeded to shoot one-hole groups at 100 yards with Remington Match .308, better than the Garand did. I had no need for the barrel on order, so I called the barrel maker and told him to give my order to the next guy in line.
That experience should have been enough to make me see the light, but wasn't. (And I probably should have bought the barrel anyway, as it will only be more expensive when I buy one in the future.) The rest of my rifles continued to receive the same treatment they had before. All the while, I was cleaning the bores of customer's rifles by the simple method of brushing them dry, swabbing with bore solvent and waiting five minutes before swabbing dry and repeating. After a dozen applications or so the dry patch would come out clean.
The next rifle was an inherited AR-15. Since I already had my own Match AR's, I used it as a loaner. It went to classes with me for students to use. It went to the club at matches for club members to use when I was the range officer on the rifle stage.
I never cleaned the bore, and only cleaned the rest of it when it started to malfunction. Unless a student swabbed the bore out, it went 15,000 rounds without a cleaning. I finally relented and cleaned it up and installed a new barrel. I sold the old one, as it was still doing one- to two-inch groups at 100 yards. The new owner wanted to build a truck gun, and was happy with one to two inches. As it will probably see no more than 200 rounds in the next couple of decades, he isn't worried about the remaining service life. While I was abusing that one, my match AR was getting kid glove treatment. As a matter of fact, it was getting better than that. I used a bore guide, a coated rod and the bore never saw a brush. Cleaning took a while, but that wasn't a problem. I'd bring the rifle into the shop on a Monday after a match and put it in the cradle. I would then swab the bore with solvent patches and dry patches between other work. If I had spent a lot of time practicing on Saturday before the Sunday match, then it might take two days of cleaning to get the bore sparkling. The rest of my rifles hardly ever got cleaned.
The cleaning progress, left to right and bottom to top: Row 1--1st nitro solvent, 1st post-JB patch, 1st copper solvent. Row 2--2nd nitro, 2nd post-JB, 2nd copper solvent. Row 3--3rd post-JB,
3rd copper solvent. Row 4--4th copper solvent, Break-Free patch.
Several things happened to change that casual system. One, I went from being a commercial gunsmith to a freelance writer. I no longer had the luxury of spending a day cleaning a bore in between other jobs. I spend much of my time at the word processor now, and can't jump up every fifteen minutes to run another patch down the bore. I also couldn't use the harsh-smelling cleaning solvents. It was bad enough coming home "smelling like a gunsmith," but to create the shop conditions at home was too much.
And finally, the match barrel didn't last any longer than the abused one did. I had thought the barrel was doing fine, but on the rifle pins at Second Chance I had a few bad runs that looked good through the scope. When I got home I bench-tested the rifle. It was shooting between one and two inches at 100 yards.
I'm still working on just why the well-treated barrel didn't last any longer than the abused one did. Until I get more data, I'm writing it off as the kind of oddity you see when testing samples of one. That abused barrel may have been the most durable barrel I'll ever see, and the other barrel may have been the most easily-worn one.
As a gun writer I've got a lot of guns to maintain. Every year during the holidays I swab all the bores, even those I might not have shot in the previous year. Dust, lint and dead insects can create a location for corrosion to start. In the controlled-environment vault my rifles live in, there won't be much opportunity for corrosion to get a foothold, but swabbing the bores out once a year forestalls even that. Each one gets a patch wet with Break Free, followed by a dry patch. The Break Free cleans out the dust and lint (and the rare dead orthopod) and the dry patch sops up the excess. I also do this with my shotguns and handguns.
Why the holidays? The hunting season rush was always far too busy for those of us at the shop to do any maintenance of our personal rifles. Right after hunting season closed, business would slow down and we could clean our own rifles, rearrange the shop and catch our breath. I'm just accustomed to cleaning rifles when the snow is deep, that's all.
The J-B patch after a dozen trips. Note the J-B is now the length of the patch, even though it was only applied to the front of the patch.
I try to keep up with the rifles used in competition, training or testing. When I can, I scrub them clean after the match or class, or when the article I'm working on is done. Loaner rifles get a scrubbing before being shipped back.
Those rifles I've fired during the year get the new and improved Sweeney cleaning system. I use three particular products for my cleaning and one general, and one of two lubes for storage once they go into the rack. My method works with both types of rifles I end up cleaning; the regulars that go to the range time and again, and the once a year rifles or loaners that I'm testing.
As soon as I can after returning from the range, I swab the bore with any bore/nitro/powder solvent, then dry brush it, followed by a dry patch. I'm not particular about which solvent I use, as all I'm doing is loosening and removing most of the powder residue that is in the bore.
To save wear on the guide, insert the rod with patch, then apply the J-B. Insert the rod guide with J-B'd patch into the action before working on the bore. Stop the rod before the patch exits the bore. If you don't you may fold or shift the patch on the jag.
Next I take a solid jag with a patch wrapped around it and spread Remington bore cleaner on it. I run the jag back and forth through the bore a dozen times. I then swab the bore out with the nitro solvent, followed by a patch wet with either Break Free or FP-10. Last is a dry patch, and then the rifle goes back in the rack.
All the cleaning I do is with a solid rod like a Dewey or Bore Tech, and a rod guide. The Dewey has a solvent port, while the Bore Tech has a patch plate. Both work, but the Bore Tech is a bit less messy. When I use the abrasive cleaners, like the Remington or J-B compound, I don't shove the patch through the rod guide. I goop up the patch, then place the rod through the guide and screw the patch in its jag onto the rod. Then I insert the rod and guide into the action. I don't know if the abrasive cleaners will scratch or cut the material of the bore guide, and I don't want to find out. Installing the patch this way is a bit fussy but keeps my mind at ease.
Is a dozen passes enough? Probably. If I've only put a couple of boxes of ammo through it at the range, then a dozen is enough. Those barrels that saw more ammo might need more cleaning, but the fouling is knocked down to the point where accuracy will still be plenty good. And the whole process takes about 15 minutes, max. The second method is the annual cleaning for rifles that have been fired, and also the thorough method for high-volume rifles like a competition AR or a varmint bolt-gun that has just come back from a trip spent thinning the rodent population. First, it gets the nitro solvent, brush and patch treatment. Then I use Shooter's Choice Copper solvent. A few drops on a patch will be enough to detect the presence of copper fouling.
In the annual cleaning, if the Shooters Choice doesn't turn green or blue in the patch, then I don't have to do any more scrubbing. Such rifles get the copper solvent swabbed out with patches wet with nitro solvent, then dry, oiled and dry patches. Those that show green or blue get the J-B bore compound treatment. Jim Brobst developed this product in the early 1960s as a cleaning method that was fast, thorough and not nasty smelling. He sold the fully-developed formula to Brownells, and they now package and sell it. What's in it? Beside petroleum distillates and abrasives (and something the state of California has deemed cancer-causing) I don't know and I don't care. It works, and makes cleaning a whole lot easier. As for the state of California, they slap that warning on anything more potent than distilled water.
I use a patch on a solid jag, smeared with a light coating of J-B. I wrap the patch around the jag, then secure the leading and trailing ends with small strips of masking tape. The tape keeps the patch in place before it gets to the bore. The tape may seem a little fussy, but it beats cleaning the chamber and locking lugs when a patch unwinds and goes where it shouldn't. It doesn't take much J-B to properly coat the patch. You don't need a lot--just an even coating. As with the previous abrasive patch, the jag gets screwed onto the rod after the rod is through the guide, then the assembly installed in the action. When I first run the patch through the bore, I do it slowly and stop as soon as the tip pokes out of the muzzle. I then place my off hand on the stock to mark the handle location, so I can cycle back and forth without the patch popping free at the muzzle. I run the patch back and forth a dozen times, then swab the bore out with nitro solvent. The nitro patch will be extremely dirty for the first couple of cycles. I then run a patch with Shooter Choice through again, wait five minutes and swab for color.
It is imperative that you have a good rod, a bore guide and proper patches. Apply an even coat of J-B around the patch. I tape the J-B patch to keep it on the jag. If it slips you won't evenly work the bore, and may miss some sections.
I repeat the process as long as the Shooters Choice shows that there is copper present. If the first patch is extremely blue, then the next application of J-B will get two dozen bore strokes. Once the test patch comes out lacking green or blue, I swab the bore with Break Free or FP-10, then give it a dry patch and put it in the rack. Depending on how fouled the bore is, cleaning takes
from half an hour to forty-five minutes.
Could I simply use the Shooters Choice to remove the copper? Yes, and I have. But the J-B is faster, and also cleans out powder, lead and (for the shotgun shooters among us) plastic. The Shooters Choice copper remover won't touch lead or plastic. A heavily-fouled bore could have alternating layers of copper and powder fouling, and a chemical clean will only take off the top layer. Without the J-B you would have to switch back and forth between powder and copper solvents, or powder and lead solvents. Also with this method I only need to use three or four light applications of the copper solvent, thus reducing exposure. When I was using just the Shooters Choice, I'd sometimes need a dozen soaking applications. What about just using the Remington bore cleaner, instead of switching to the J-B? The Remington cleaner is good, but the J-B works faster, and the paste composition of it makes it easier to apply right where I need it.
If the J-B is abrasive, don't you have to worry about harming your bore? And what about chrome-plated bores? The abrasive used is non-embedding, and won't grind your bore out. It is softer than the steel but hard enough to work on the copper, and lots softer than the chrome. It hasn't harmed any of my barrels after years of use. Those who wonder about its effect on the gas system of self-loading rifles needn't worry. The small amount that gets left in the gas port isn't enough to cause a problem in the gas system, and is soon blown out anyway.
My method works faster than brushes and solvents, eats up all the fouling types, not just one, and has much less smell than a straight application of solvents. Just what I need to work over a couple of dozen rifles in short order.