Fouling Control or Not?

I attended the 2024 BPCR Nationals at the Whittington Center in Raton, New Mexico. The matches were held in early July, and the range fully lived up to its reputation of hot and dry conditions, with no shortage of mirage and rapidly changing conditions. In contrast, there was a 22 BPCRA match before the black powder big bore match. Thunderstorms occurred daily, and there was enough moisture to grow mosquitoes in the desert. At one point during the BPCR match, the temperature hit 91 degrees Fahrenheit, with humidity levels in the teens. This was unusually warm, considering the range is at an elevation of 6,500 feet.

Spotters questioned many shooters, “Why was that shot way over there?” and “Did you see how high that was?” Black powder fouling control was a serious topic of discussion on the firing line. There was a range of methods were being used; some worked well, others not so much. One could find diverse fouling control methods on the firing line: blow tubes, brushes, jags, paper patches, cloth patches, “weasels” and felt wipers along with Delrin cleaning rods and carbon fiber rods. Patches and wipers were soaked with various forms of liquid (some with secret ingredients), or the universal solvent – water.

Introduction

Upon ignition, about half of the black powder charge turns into gas; the remainder is solid particulate matter, mainly combustion products. Some of the solids are ejected from the barrel, while a portion adheres to the inside of the barrel. As the temperature increases and the humidity decreases, these particulates seem to cling even more strongly to the barrel interior. Although the black powder is not hygroscopic (having the ability to absorb and hold water molecules from the environment), in its original form, it is very hygroscopic after combustion. Due to the hygroscopic properties, the fouling can be removed or softened by introducing water. This can be as simple as moisture from a blow tube or as aggressive as a nylon brush on a cleaning rod with a well-soaked patch.

The residue will attract and retain moisture. Given mild conditions, such as 70 degrees Fahrenheit with 50 percent humidity, a blow tube is more than adequate to soften the fouling. A lightly moist patch will also work, keeping the fouling soft or completely removing it, allowing for accuracy retention. If the fouling is not controlled, the bullet can be deformed, and some lead can be stripped from the bullet, leaving it in the bore with the hard fouling. Hard fouling can also result in erratic velocity.

Using a well-known bullet lube is the first step to controlling fouling. The bullet lube allows it to ride on a lubricant film as it travels down the bore. You would soon have significant leading if the bore were dry and the bullet un-lubed. With a lubed bore, it becomes more difficult for the fouling to stick to the bore surface. The bullet lube helps keep the fouling soft so that it can be further softened with a blow tube or removed with a patch. Not all lubes are created equal, and not all are specific to black powder. I suggest that any shooter starts with a known commercial bullet lubricant such as SPG Lube, DGL or another proven lube. This will at least eliminate one variable within the fouling control process.

The proper bullet lube, I believe, can result in better accuracy. Schwartz and Dell, on page 194 of their book The Modern Schuetzen Rifle, share some exciting work and beliefs – “I have now determined that even if a bullet lube meets all other criteria such as: prevent leading, suitable melting point, long term stability, and desired hardness, there is a definite accuracy difference with different lubricants.” A series of five, 10-shot groups were fired from a machine rest at 100 yards to test various lubes. Dell found the smallest groups had an extreme spread of 0.70 inches, and the average mean radius was 0.27 inches. The largest groups were 1.17 inches extreme spread with an average mean radius of 0.43 inches.¹  The results indicate a 37 percent reduction in the average mean radius from the poorest performing lube to the best lube. For reference, the average mean radius is the distance from the group center to the center of the bullet impact, averaging 50 shots. An average mean radius of 0.27 inches is excellent. In conjunction with the machine rest, Dell used a muslin wind tunnel, as Doctor Mann did.

This reinforces the importance of bullet lube. Many shooters wipe between shots and conclude that since the bore is reasonably clean, the lube does not matter. I don’t share that view. Dell’s work used cast bullets and smokeless powder, which should have been fouling-free, yet the bullet lubricant still made a significant difference.

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Fouling Control

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Blow Tubes

The entry point for fouling control is the blow tube. It is a clever device that you can slip into your pocket and have readily available on the firing line. Mostly, it is for conditions where we have some level of humidity.

I must admit I have known a couple of shooters who can use a blow tube in what I would call harsh, dry conditions, and they make it work. I am not sure how they do it. But I believe they are genuine riflemen and have something figured out. They use a good lube and know how to use a blow tube. Proper use of a blow tube is not like playing a kazoo. Real masters know how many breaths to use for a given condition and seem to pace themselves regarding how fast they shoot. They are also meticulous in breathing through their nose and out through the mouth. This picks up the maximum amount of moisture to soften the fouling. If you watch a blow tube master, you might notice their blow tubes are very short. It does no good to fill a long blow tube with moisture. The moisture belongs in the bore.

Wiping the Barrel

If you are not using a blow tube, you will need a cleaning rod and, on the end of the rod, some implement to push a patch or something else down the bore. I use a jag for my 38-50 because it works well with my preferred patches. Although a nylon brush (rifle length, not the short pistol brushes) works exceptionally well and has the added benefit of loosening minor fouling on the return trip that may be left in the bore after the patch has fallen off at the muzzle, there is always a bit of moisture left. The brush can give the bore more attention when withdrawn. I use a nylon brush when shooting my 45-90 with the same patches I use in the 38-50. I do it for a couple of reasons. First, when I arrived at the range with my preferred patches and patch liquid, I did not have a proper jag but a 45-caliber rifle nylon brush. It worked so well that I stayed with it. I should mention that I shoot the 45-90 in target rifle matches where the barrel is exposed to direct sunlight, and fouling seems to stick more readily. Another option is a bronze brush. If there is any fouling, a bronze brush will undoubtedly resolve it. I do not think they harm the bore of a carbon steel barrel. However, I have some stainless match barrels, and the manufacturer states that a bronze brush should not be used. This leads me to believe I should not use them as a fouling control method.

Weasels et al.

“Bore weasels” are a single-pass bore cleaning system. Some are as simple as parts cleverly assembled from a hardware store. The accompanying photograph shows that some weasels are custom-made by clever lathe-owning people. Weasels work well. Just be careful not to get the barrel too clean and too dry. This condition can sometimes encourage leading, depending upon the interior finish of the barrel. Buffalo Arms Company offers a Bore Wiper Cleaning System commercially. It consists of a solution-impregnated wool wiper and squeegee, and excess liquid is removed with one pass. The shooters I have spoken with are pleased with the system.

Rods

There are a couple of choices for cleaning rods between shots. Probably the most popular is a Delrin rod, followed by a carbon fiber rod (Tipton) or, occasionally, a steel rod. I am biased against the Delrin rods. They are too flexible. In use, they constantly rub against the side of the bore in random places and cause wear. If you use a Delrin rod, feel the surface of the rod with a finger after you have fired 10 or 15 shots, followed by cleaning each time. There will be considerable ultrafine grit on the rod, which, over time, will wear the barrel. I did not believe this could happen until a gunsmith set up a bore scope on a BPCR barrel cleaned between shots with a Delrin rod. The worn spots were easily seen. How long before the barrel loses accuracy? I don’t know; I prefer not to find out. With any cleaning rod, it is essential to wipe the rod clean with a rag between relays to remove grit.

Patch Materials

Each BPCR shooter has their idea of a good patch material. Based on my casual surveys, the Arsenal patches are the most popular. They are inexpensive and work well on a jag or nylon rifle bush. I used these for many years and still use them for barrel-cleaning chores. I understand that you can also wash the patches and re-use them. I never did this when using them because I wasn’t aware this worked. However, knowledgeable shooters have told me you can wash them, and they work even better.

Cotton patches have been around since the dawn of time and also work well. I think they work better than the Arsenal patches, as the weave seems to grab more crud, and the cotton holds a bit more moisture. They can also be washed and reused.

My preferred patches are two-inch squares of microfiber cloth. If you have ever handled a microfiber towel, it wants to stick to your fingers. It does the same thing to the fouling. I purchased my towels from Harbor Freight, but I am told they are even cheaper online. The packages of towels come in mixed colors, so you end up with green, yellow, and orange patches. A fellow at the Nationals asked if I was wiping my bore with recycled clown suits! I have washed them many times, and they still work. When you have new, recently cut patches, the small colored “pills” go everywhere; clown glitter. After the first washing, the glitter goes away. Indeed, this is the Scotsman’s method of fouling control.

I have been shooting BPCR since 1992, and I thought I had seen almost everything. Well, I have not. I discovered that you can use cotton balls to wipe your bore. The balls are first pulled and flattened out a little bit. They look like a fat flying saucer – at least fatter than the flying saucers I have seen. They must grab some fouling; I have no personal experience, so I cannot expand upon their effectiveness.

Catching Everything

If you don’t pick up after yourself, the match director may have an uncomfortable conversation with you. Nobody wants shooters to leave their patches behind on the firing line. You will see many methods of catching patches as they fall off the muzzle. I used to use a plastic shoebox. It was light, handy, and easy to clean. The only drawback was the muzzle blast would make all the patches jump at every shot. Most would land back in the box, but some would escape, especially if it was windy. A better solution is an egg basket. The holes in the chicken wire let the gas through, and the patches stay put. I did not come up with this idea. I do not have novel ideas, but I am a habitual novel idea implementer.

Solutions

Every patch needs some solution or moisture to remove the fouling adequately. Tap water will work, but it can cause rust within the barrel. An alternative is mixing water and water-soluble oil from auto supply stores. Mix 90 percent water and 10 percent water-soluble oil and use to moisten the patches before use. It is effective, and the oil stops the rust. Muzzleloader slug gun shooters are careful to oil their bores after cleaning before loading the next shot. A small amount of oil in the bore is not a bad thing.

RAM is a popular wiping solution. The name is an acronym for RV antifreeze, Alcohol and Murphy Oil Soap. The mixture is 3 parts, 2 parts and 1 part, respectively, of each of the named components. I don’t think the proportions are hard and fast as the amounts have varied depending on who I ask. The alcohol acts as a surfactant, or as some say, it makes water “wetter.” If you have ever seen a drop of water on a well-waxed car, you probably noticed it beads up due to the surface tension. A surfactant reduces the surface tension and allows better liquid penetration into the fouling. Murphy Oil soap, blended with water, has also been mentioned as working very well.

Antifreeze, typically Volkswagen or Audi, is a popular wiping solution, either straight or mixed with water. It works well to remove fouling. I find the antifreeze slippery, which seems to get on my hands, along with the cleaning rod and the rifle. Once the handle on the cleaning rod is coated, it becomes hard to hold on to. Alternatively, I have had many shooters tell me the antifreeze is not slippery and does not create a problem. Well, to each his own.

Regardless of the solution your patch material is saturated with, it is good to have a method to squeeze out the excess moisture. The microfiber patches hold much more liquid than the arsenal patches, making a mechanical process necessary to reduce the moisture content. A ricer from your local kitchen supply store works well, and with some practice, it will result in uniform moisture removal.

Methods

At the risk of stating the obvious, to be a consistent shooter, you need consistent methods of fouling control that will work under all conditions. Detecting fouling starts with knowing how your rifle shoots under good conditions, both in accuracy and fouling control requirements.

We will assume we use patches moistened with our particular solution, using a cleaning rod with a nylon brush. Under mild fouling conditions, we should observe what the first patch looks like as it exits the muzzle. It is not necessary to pick the patch up; look at it closely before it falls off the brush. Complete the same process on the second patch. My second patches have minimal fouling, and I know what they look like. Careful observation has taught me that when the second patch looks like the first dirty patch, I am picking up some fouling, and it is probably time to run an additional patch. If the third patch had minimal fouling, I know the bore condition is good, and fouling is not an issue.

When running a wet patch down a bore that I am reasonably sure has fouling, it feels like a bit of glue inside the barrel, resulting in drag on the patch. Some shooters have described it to me as chewing gum inside the barrel. When I feel this, I know it is time for additional patches.

If it is a hot, dry day, it is best to detect the fouling by observing the patches or the feel of the rod when cleaning the barrel. Typically, fouling will cause high and low shots, although there will also be random shots. In general, accuracy will be lost, and with heavy fouling, staying on target with any regularity can be difficult. If we wait until we have wild shots, our scores can suffer greatly.

All this patching might cause some problems related to cartridge case separation. The brass cannot grip the chamber walls if the excess liquid is left in the rifle’s chamber. This can cause the brass to slide within the chamber and cause a case separation. A chamber swab is recommended to remove any excess moisture from the chamber. This is particularly true with longer cases such as 45-90 or 45-100. I am not overly concerned about extra moisture in the bore; powder gas escapes past the bullet, carrying some lube and stripping any excess wiping solution out of the bore in front of the bullet. Indeed, some moisture is left behind, and this, combined with a quality bullet lube, helps prevent the fouling from sticking badly.

Target Rifle Match Versus Silhouette

If you think fouling control is difficult during a Silhouette match on a hot day, try a Target Rifle match, where the barrel is in full sunlight. In addition, most shooters use larger powder charges for longer distances, which increase the barrel heat. The additional heat increases the degree of difficulty in regards to fouling. The match would start very early in the morning when the Target Rifle Nationals were held in Raton. As I recall, firing commenced roughly at 7:30 a.m., dependent upon light conditions since we were using iron sights. During mid-range matches, the first target is at 200 yards, and with the cool morning, only one patch was required to keep the fouling under control. At 300 yards, two patches were used after each shot. Later in the day, when it was hotter, and we were firing at 600 yards, it was necessary to use three patches to maintain accuracy.

We Were Desperate

I was shooting in a Creedmoor match (800, 900 and 1,000 yards) with the late Andy Fautheree in the early days. It was a scorching day; we were new to the game and had blow tubes for fouling control. It was not working. Andy came up with the idea of running a dry bronze brush through the bore after each shot, followed by blow tubing. Pushing that bonze brush through the bore made an awful noise and deposited a quantity of dry fouling into the action. After the brush treatment, we would blow tube, load, and shoot. Sure, it made a mess, but we were desperate, and it worked. I hate to think what it might have been doing to the rifle bore!

How To Detect Fouling

To prevent “fouling out” during hot, dry conditions, know what your patches look like upon exiting the barrel under normal moderate weather conditions. Have a plan for when fouling occurs. Trust me, it is like “cross-firing” in a target rifle match. It is not a matter of whether it will happen, but when.

Observe the inside of your barrel, and it only takes a moment to glance down the bore after patching to see if any fouling remains. We are not looking for ½-ounce chunks; we are looking for delicate pieces. Typically, they will be on top of the lands primarily because they are easier to see. Fouling is a gradual process. There is always a small amount of fouling present after we clean. If an adequate amount of the fouling is not removed after each shot, the “wheels will come off,” and a shot wide of the target will follow.

Conclusions

Fouling might be a minor issue if you shoot only in locations with high humidity. However, if you ever shoot in the country’s western half, you can encounter some arid conditions exacerbated by high temperatures. If your fouling control methods work in the latter, you have solved one of the problems involved with shooting well.

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References:

^1. Schwartz, Wayne, and Dell, Charles. The Modern Schuetzen Rifle. Christiansburg Printing, 1999.