Old Glory Gunsmith Shoppe: Bore Cleaning the AR-15 (and other bores)

As a former US Army armorer, as a secondary Military Occupational Specialty (MOS), I can tell you I have come up against some dirty, fouled weaponry. Therefore, the importance of cleaning your weapon to ensure consistent accuracy and long life, cannot be overemphasized. I cannot remember how many times I had to refuse to accept an M16 that was not clean from turning in their assigned rifle to the unit arms room. It did not make me popular, at times, but it was my duty to ensure that all weaponry in the unit arms room was battle ready.

Indeed, if it was in my nature, I could have had a part-time business going, accepting gratuity for cleaning their firearms for them properly after accepting its turn in.

Having to replace barrels of an M16 because of neglect, is not only detrimental to the reputation of the unit armorer; but also a waste of taxpayer funds. Throughout my career that was one of my pet peeves: wasting precious funds allocated to the US Armed Forces. Later in my career, when I went into administrative security avocation from being an Infantry soldier, the awareness that as the echelon increases up to the Pentagon, that waste can be astronomical. It is one of the reasons why I turned down an offer to be assigned to the Pentagon, instead of fielded units.

As aforementioned, there are two important reasons why cleaning your weapon bore properly should be of utmost importance to firearm owners and operators. As stated, it improves accuracy and maintains that accuracy. Second, putting a fouled, dirty weapon in storage invites the formation of rust, which will pit any barrel of any weapon.

In some hunting situations (or combat situations), if you have fired below twenty rounds and will use it again, you can get by holding off cleaning until the following day.

When you purchase a new firearm, whether it be a pistol, shotgun or rifle; the importance of the break-in period cleaning ritual cannot be overemphasized. In addition, certain types of firearms require certain considerations in the process of proper cleaning. The M16/AR-15 with the star-shaped chamber is no exception. Real Avid has come out with a special star-chamber cleaning pad that comes twenty to a package that is excellent for cleaning those chambers. Wish I had such a thing in the US Army. Tapco sells twenty for less than Real Avid, but do not know at this writing if the quality is also less. Amazon sells a pack of twenty star-chamber cleaners that come with gas-tube cleaners for $14.95.

Browning M1918A2

In addition, whether it be an M1918 BAR (Browning Automatic Rifle) or the new piston-driven assault rifles, particular attention should be made to the gas system that affords the weapon to fire in semi-automatic or automatic cycling consistently and efficiently.

Hoppe's Snake Bore Cleaner

There is an argument that has been going on for decades among gunsmiths and other experts whether it is true that bore fouling is accumulative or not. They claim that if you fire one round or 1,000 rounds, there is no difference in the degree of fouling. I disagree, as do many armorers and gunsmiths will back me up – fouling is worsened as more rounds are fired. After 500 or 1,000 rounds are fired without proper cleaning, in order to get the bore back in shape, it will probably require abrasives like J-B Non-Embedding Bore Cleaning Compound and a strong copper solvent. The compound itself does not harm the bores, unless certain strong solutions is left on the metal longer than it takes to clean and rinse it, but the back-and-forth motion of the flexible cleaning rod will wear out the bore lands. The land is the part that sticks up above the bore grooves, which is only paper thin; and it can be worn down even in barrels made of the best steels. Barrels can be destroyed in this manner, and why it is important to never use aluminum rods and spend the extra money to purchase quality coated rods that the professional gunsmiths use. For field cleaning until you can get back home for a thorough bench cleaning, the popular “snake” (bore snake) is acceptable and easy on your bore.

M-Pro 7 Tactical Kit

M-Pro 7 has a Tactical Assault Rifle Bore Snake Cleaning kit complete with small bottles of M-Pro 7 gun cleaner and gun oil; a second choice over the tried and proven Break-Free CLP that has protected US Armed Forces firearms for decades.

But to remove stubborn fouling, it takes a proper, professional cleaning rod, solvent, and attachments. By using a field cleaning kit when out at the range, there is less chance for any fouling buildup to occur.

For oiling and protecting I always use CLP, but like the M-Pro 7 Copper Cleaner for copper and fouling cleaning jobs. Of course, there are other quality cleaning compounds out there, as aforementioned, which are also on my gun cleaning bench shelf.

So, frequent cleaning reduces fouling buildup, makes fouling easier to remove between firearm use, and protects the bore of your valuable firearm that you may want to make your family heirloom.

I would like to mention that if you are going to store your firearm more than a few days, give a good cleaning and oiling. If your firearm is stored in a gun safe, spend the extra money and get a quality dehumidifier. Conscientious gunsmiths store their customers' firearms in a safe of safe room always equipped with a dehumidifier device.

Carbon and copper are two forms of bore fouling and each requires a bit different technique; keeping in mind that either removal process provides an increased danger of causing damage to the bore.

To begin, you need a quality one-piece (not like those threaded rods the military issues) and ensure that the rod diameter is correct for the caliber of the firearm being cleaned. Never use a .22-caliber cleaning rod to clean a .30-caliber bore. The smaller rods flex more and the increased flexing is asking for potential bore damage.

The rod needs to be just long enough to pass through the length of the barrel. AR-15 and similar rifles are generally 16 to 20 inches. I prefer assault rifles that have a 20” barrel. The rod therefore should match the barrel, so if you have a 24” big game hunting/sniper rifle – use a 24” rod. When you attach the bore patch tip, brush or mop – it extends a little beyond the end of the barrel.

Rod handles must rotate freely, the more expensive cleaning rods have quality handles that do this properly; important in order to prevent damaging the crown – another factor in bore accuracy. So set up a separate rod for each bore length of your firearm collection.

I uses one rod for bore brushes and a second rod for patch, Remington squeegee, the new pellet cleaning tips, or brass jags and O-Ring jags that justify their extra expense. I prefer the round swabs versus the square swabs, and spend more for the quality material – cotton twill and flannel. Swabs (patches) are for general cleaning and applying foul cleaners, but an important part of your gun cleaning ensemblé; the bore mop also serving its purpose. Mops are usually used on smoothbore firearms like shotguns and antique smoothbore muzzle loaders; but I like to use them for certain foul cleaning chemical applications for bored barrels.

Invest in a bottle of blue Loctite threadlocker to apply to your threaded rod tips. This keeps the tip from unscrewing during the cleaning process.

As I have written in other articles concerning firearm cleaning, the best approach to cleaning the bore is to run it through the breech and remove the patch when it exits the muzzle. This is a method that requires patience, that was not always applied by my comrades in arms serving in the US Army. When using a bore brush properly, breech towards muzzle and back again; if you use the Blue Loctite, it will prevent the tip coming loose and screwing up your crown. Thus the reason why I use a second rod setup for that purpose – saving time and still doing it right. Using the proper quality bore brush is also something you should consider. Cheaper ones are just that – cheaply made and not authorized gun manufacturing material.

Bore guides are good to use, as described in my breaking-in article, but do not purchase plastic bore guides. Use metal bore guides, and I recommend those made by JP Enterprises or Wheeler Engineering that are tight fitting because they are fitted with O-rings that centers them properly.

A good cleaning brush is also a necessity, although most folks use a simple toothbrush, but do not use it for cleaning hardened carbon fouling.

Another detail often overlooked is that during the cleaning process, wipe the cleaning rod periodically with a clean rag.

Springield Armory M1A

For rifles like the M1A, use bore guides that fit over or inside the front flash suppressor. Driving the bore rod straight is essential.

The bore patches should be the correct size for the bore being cleaned, as well as clean good quality bore brushes, including the chamber brush that the military folks have in their cleaning kit for the M16, M60 and other firearms. A good aerosol gun scrubber or Windex without ammonia is excellent for keeping your bore brushes clean. Often this step is overlooked and they are cleaning a bore with a dirty, foul encrusted brush.

Back to the bore brush: make sure the windings in the middle of the brush do not terminate at the front (worn out) and not expose the rough end that can dig into a bore. Ammonia-free Windex should be used after each cleaning to remove petroleum-based bore solvents and copper solvents that have ammonia in them. Traces of ammonia left in the bore can combine with chemicals in the burning of gunpowder to form a substance that can corrode a steel barrel. I would like to add here that when using those chemical cleaning compounds it would not hurt to put on a respirator mask, but at the very least, use them in a properly ventilated area.

Kano MC-7 Shooter' Choice

For normal copper cleaning, traditional Hoppe's Bench Rest 9 Copper Gun BoreCleaner is good (or Shooter's Choice) to use for normal copper cleaning after breaking in the barrel. You can leave Hoppe's Bench Rest to sit overnight because it is not a fast-acting, strong solution; thus more forgiving to amateurs. Letting it sit after application for 15 to 30 minutes is recommended before swabbing and rinsing out. There are several good bore solvents produced, but with any of them – follow the recommendations of the manufacturer. NEVER mix different brands of solvents. For example, never use Hoppe's No. 9 on a bore brush to remove carbon fouling and then follow up with Shooter's Choice Copper Solvent on a patch for copper fouling removal. Clean the bore brush and use a clean patch that has no residue of foreign chemical. You can use the same brand chemicals between fouling and copper residue cleaning – but be safe and clean your bore brush between applications. J-B Bore Cleaner will not have an adverse reaction with chemical cleaners because it uses abrasives to clean.

M1 Garand

All of these tips and recommendations will be beneficial to those who collect and fire military firearms from the .30-caliber rifles like Springfield, Enfield, Garand, M1 Carbine, and M14 to the modern M16 and its assault rifle variant children. But, of course, good cleaning techniques and practices apply to all firearms.

Cleaning rod flex seems to be the biggest threat to bores. Too many shooters believe their bores are deteriorating because of the number of rounds and the friction of the bullets moving down the bore that causes the wear. Even coated cleaning rods of good quality will flex and scrape the lands of a barrel that causes more wear than shooting. The smaller the cleaning rod, obviously, the greater the flex – as those with “universal” cleaning rod kits can attest. I mentioned the importance of not using worn bore brushes, replace them with new tighter ones. When using a new tight bore brush, you can feel any flexing from the rod more markedly. I rehash the important aspect of bore cleaning …

Rods that are too long are also a problem, making it harder to keep the rod centered when not using a bore guide.

After ensuring that your bore brush is not worn out, use plenty of non-ammonia solvent on the brush and bore. Besides, dry bores are harder to push the rod tipped with a brush than one with cleaning solution. Do not use the nylon bore brushes and use a full caliber brush.

When using abrasive pastes, like J-B, most folks push a patch coated with it forward until it almost comes out the muzzle and then pull it back to the chamber. Rod flex will occur the second time you stop pulling and begin pushing forward. Spend the extra cash and get a quality bore guide. You may not feel the flex, but if you inspected the barrel with a borescope after a period of time you will see one or two lands wearing down more than others. That is because the rod is not driven straight down the bore. Take your time and slow down your rod strokes to reduce that harmful flexing.

Now onto fouling process …

Copper fouling gets attention like carbon fouling because you cannot always determine its presence like the bluish-green coloration left on patches with copper fouling. Without an expensive borescope, you may not be aware that carbon fouling is lurking in the places where land and groove meet.

Carbon fouling is baked on in the process of firing, but copper fouling is caused by copper being stripped off the bullet as it squeezes down the barrel and out the muzzle. Carbon requires some kind of abrasive compound while copper is removed with an ammonia solvent.

To properly clean fouling, start with a quality metal bore guide properly in place and push three patches soaked with Hoppe's No. 9 through the bore to flush out powder residue. Then rod a few strokes with a bronze bore brush that will tackle carbon fouling. Nylon bore brushes are not good for removing carbon fouling, but they are good for use with ammonia solvents that remove copper fouling. Never use hot ammonia solvents with a bronze bore brush. Hot ammonia solvents will attack the copper content in the bronze brush because it contains 88% copper alloy and 12% tin. Stroke the rod until the brush seems to be drying out. Flush the bore out with a couple more patches of Hoppe's No. 9. Never try to reverse direction of a bore brush when it is still inside the barrel. Now on to the copper fouling cleaning …

X-Treme Rifle Rods

Switching rods or cleaning a rod used for carbon fouling, wet patches of Hoppe's Bench Rest and wait for the ammonia to chemically react with the copper in the bore. This is a good time to disassemble the bolt carrier and charging handle into an ultrasonic cleaner, if you have one.

Every 10 or 15 minutes, until copper coloration no longer appears, run a clean patch through the bore.

Once the copper is removed, clean the chamber with a clean chamber brush and aerosol gun scrubber. Ensure that you use a gun scrubber that does not contain chemicals that would have an adverse affect on the copper solvent. Do not soak bore with gun scrubber because you may remove the copper fouling solvent and be tricked into thinking the copper fouling has been removed. Use the aerosol for rinsing excess solvent from the muzzle and flash suppressor – but not sprayed directly down the barrel. You can also use cotton swabs and rags for this action.

After the patch comes out with no copper fouling, finish up cleaning the bore and removing the solvent with a patch or two of non-ammonia Windex; and then follow with four clean, dry patches.

If you think it necessary, run a patch of J-B Bore Cleaning Compound back-and-forth in a scrubbing action – reversing the direction of the patch just before exiting the muzzle. Reversing a second time will cause rod flex. You can use a mop or snake mop for this purpose. Use the J-B for stubborn copper fouling. Its abrasiveness is mild like that used for polishing metal, so it is safe. Use J-B compound for stubborn chamber fouling buildup, most common with rifles that have not been properly cleaned or neglected. A rise in chamber pressure with blown cartridge primers indicates the chamber is fouled badly. J-B can help with that problem.

Now you want to preserve your barrel after your cleaning process. Important: J-B Compound or other abrasive cleaners is best used for break-in period; and use the recommended solvents for cleaning afterwards. [See long-range precision rifle video at end of article]

Brownells, a professional gunsmith and firearm enthusiast supply company, conducted a professional study on corrosion and rust prevention. WD-40 (used in Army) and Boeschield T-9 and Break-Free CLP scored well. If you are going to store your firearm, I suggest Boeschield saturated on a clean patch and work it into the bore. Pay attention to the crown, one of the first places hit by rust. A pitted crown will definitely affect accuracy. Spray a shot of Boeschield directly into the chamber and barrel extension – turn the rifle around and spray the front of the muzzle, crown and flash suppressor. When you take your firearm out of storage to take to the range, spray with gun scrubber followed with a patch of non-ammonia Windex through the bore and follow with a dry patch.

Procedure for cleaning when breaking in a new firearm is HERE.

Using proper and non-corrosive ammunition will also protect your bore. Use common sense and pay attention to manufacturer recommendations when using reloads. Best to reload your own ammunition instead of purchasing and using another person's reloads. Safety is also a factor.

The AR-15, civilian version of the M16 is quite a hardy rifle and can be purchased with an upgrade to 7.62mm/.308-caliber versions. All of the aforementioned cleaning tips and recommendations apply, indeed, they apply with all firearms.

VIDEOS:

Copper/Carbon Fouling ...