An Observation on Fouling

[Jim Leinicke 7368V]

As a rule, I shoot relatively light, conventional skirmish loads of faster burning powder (Goex 3fg or Swiss 2fg). I have not really shot much GOEX 2fg simply because I tend to get a lot of fouling in equivalent 2fg loads. However, for deer hunting I load 70 grains GOEX 2fg and the Hodgens skirmish bullet because it is very accurate, flat-shooting, and absolutely devastating on a deer. When I cleaned my rifle after last weekend's hunt (Three rounds fired) I noticed again, as I have noticed before, that there was no appreciable fouling in the barrel. In fact, I believe I could have simply run an oiled patch through the bore and let it go at that.

I am wondering why a 70 grain load of 2fg is so extremely clean burning, while a 43 grain load leaves appreciably more fouling? My guess is that the much higher breech pressure of the hotter loading results in a much more efficient use of the powder. Does anyone have any thoughts on this?

Jim Leinicke
7368V

[P.Altland]

Talked to Frank Garrett once and he said that he used so much powder in his Sharps carbine that barely any smoke left the barrel. More powder + back pressure = more chamber pressure and more efficient combustion. Ever look at someone's barrel who blows off their powder charge at the end of a relay without loading the bullet (which is against the rules)?


Sent from my iPhone using Tapatalk

[RaiderANV]

Yes......very against the rules and a penalty.

[John Bly]

Jim, I've been shooting black powder cartridge silhouette for over 20 years now with a 45/70 and a 40/65. Common wisdom among fellow shooters is that to reduce fouling you increase the powder charge. I know it sounds odd but the reasoning is that the higher charge increases pressure which increases the temperature of the burning powder which in turn results in more complete combustion thus less fouling. Another reason could be that the higher pressure results in more ejecta from the muzzle leaving less fouling in the barrel. It could be both. Take your pick.

[jonk]

It's true with smokeless as well. Try loading about 25 gr of 4895 in a 30-06 case vs. 50 and you'll get a lot of unburnt powder. Simply less pressure from a smaller charge to complete combustion. With smokeless it manifests as unburnt powder, with black as more residue.

Oddly, the most accurate load for my musket is using 3f. For my carbines it is 2f, using a lighter load. So just when you think you have a good reasoned approach, out the window it goes...

[Jim Leinicke 7368V]

Now that you mention it, I used to load 28 grains of IMR4198 and some pretty light .45 bullets in an old trapdoor when I was a kid, and there were usually unburned grains left in the breech with those light loads. Anyway, I have heard from all sorts of sources that the best blackpowder load in any breechloader is all the powder you can cram into a case, and I suppose this efficiency of combustion issue is what the old timers were referring to. Anyhow, I think over the winter I may do a bit of experimentation with heavier 2fg loads just to see how I do with them.

Thanks for the responses, folks. And have a Happy Thanksgiving.

Jim Leinicke
7368V

[jonk]

Well now you've opened a can of worms with the whole "best cartridge load is the most bp you can cram into the case."

The use of fillers (COW, kapok, carded wool, etc.) says a lot of guys would disagree. Me being one of them. On a lark I tried 40 gr of 3f in my trapdoor with cornmeal filler. Outshot a compressed case full and no two ways about it. My buddy Ian who shoots BPC silhouette matches has even found that on a calm day, said load will still knock down targets at 550 yards in a silhouette match and he really had the other shooters talking as to what he was shooting. As that's another can of worms, I'd say that all the filler there is having a sealing/scrubbing effect on the fouling, which is another option to consider. The same light load of smokeless that doesn't burn completely often WILL with the use of a filler; which is again, yet ANOTHER can of worms as it is a different ball of wax from bp fillers in terms of doing it safely.

However, the general idea of more powder equals a cleaner burn is very true... the Brits for instance when they switched to the .303 initially used a very heavily compressed load of black, and were getting close to smokeless velocity and cleanliness...

[John Holland]

A great topic & thread going here!

I have a question in the same vein as what is being discussed, but in the opposite direction. What are your thoughts on breech loading black powder cartridges that are using light loads, no filler, and an air gap between the powder and the bullet? Example: A .44-40 with 17 grains of 3F and bullet seated at the neck, which leaves a large air gap. So, when loaded and fired from a horizontal position the powder at best is laying along the bottom of the case from the primer to the bullet. The primer has to be igniting the powder across the top of the spread out powder charge. I know people doing this and have seen some extremely tight groups being produced by this method. All of this takes me back to the Buckskin Report days and their Black Powder Cartridge magazine where the scared me half to death with the word "detonation" of a powder charge if things weren't loaded properly....whatever that is. I never did understand exactly what they were trying to impart to their readers!

Do any of you have any thoughts on this?

JDH

[bobanderson]

I've also shot BPCRS for about 20 years. In my experience, the degree of fouling is more affected by the type of powder and the quality of your bullet lube. I started out shooting "Elephant droppings", then went to Goex cartridge grade, Swiss in 1 1/2 and 3f and finally Goex Express, which is the predecessor of Old Eynsford.

In each instance as I changed powder quality and upped the charge to maximum capacity and even compressed loads, the fouling was always watched closely because in a short timed string of shots, a fouled out barrel can destroy a score.

My take is fill the case to capacity with a fine granulation, quality powder and use a good lube (I'm NOT a fan of SPG) and fouling is at it's least. I've noticed that you can look down the barrel after a shot and if you have good fouling control, the residue is accumulated at the bottom of the barrel and the top half or so is almost clean. In breechloaders, shooting cast bullets sized at least .002 over groove diameter will go a long way in reducing fouling buildup, IF your lube is good.

JDH,
I've shot less than full cases (17 grains of 3f) for years in a 45 Colt at breakable targets at skirmish type events (See Black Powder Through the Ages on Facebook) and have had excellent accuracy. I think the whole detonation thing is more with smokeless shooters using small charges of fast pistol powder, like Bullseye.

[jonk]

Well detonation with any powder is another interesting question. I think that with ANY powder, black included, the culprit is one of two things. Either:
1. If the powder is below the level of the primer and the flame can flash over the top, two sections of the power may be simultaneously ignited, creating a secondary explosion effect when the two flame fronts meet; or
2. The primer is of sufficient force to blow the charge- and bullet- forward, often wedging it an inch or so into the rifling, but only partially igniting the powder column. The bullet at this point acts as an obstruction, and if maximum loads are being used, can raise pressures to an unpleasant extreme.

In the smokeless world, this is usually caused by using too slow of a powder for the case. Actually, very FAST and easy to ignite powders, such as bullseye, are largely position insensitive, and it isn't an issue. They conflagrate fast enough that it isn't a problem. Using a coated slow powder- especially ball or some very slow stick powders- it can be more of an issue. Even then, it's a once in a blue moon thing, something we've heard about but few shooters (luckily) ever see. Naturally, too HIGH a charge of a fast smokleless powder just creates a bomb in front of your face.

Which brings to point the question of reduced loads of black with an air space.

First off: a lot of companies and even militaries had loads using less than a case full of powder. There is certainly a question of load density at work here. A sharps rifle charge for instance creates an air space issue by its very nature, and isn't an issue. My personal thought is as long as load density is 2/3-3/4 at a minimum, no issue will be had. Not that I advocate trying it, it's each shooter's own decision.

My gut feeling is that it is more issue in a muzzle loader due to point 2 above. The primer cap has enough force to blow past some of the charge, ignite a small part of it, expand a bullet skirt or upset a patch into the rifling, creating an obstruction that pressure has to really build behind to get moving. Isaac Newton at his finest; getting an object moving requires a certain force, and KEEPING it moving- and accelerating down the barrel- requires LESS force than to get it moving again from a dead stop, and it is the gentle push created by initial ignition that gets it moving safely. As a shooter cannot reliably estimate load density with a front stuffer short of "fully seated on the powder" not seating it reliably to the powder creates this possibility. Such control IS however possible in a cartridge gun.

That said, There is still the question of point 1 above. Secondary explosion effect. If you get below a certain load density (case being filled a certain percent) there is still the chance of two wave fronts of flame meeting.

So: to sum up I would personally judge a muzzleloader to be shot safely using the ball seated fully only; a breech loader or other cartridge gun to be safe so long as the air space doesn't exceed a certain percent of the case volume (your call on what that may be).

Personally I just use filler or wads to take up said space, as it provides a good secondary characteristic of a gas check effect.

[Kevin Tinny]

Hello:

A Phd explosives chemical engineer and past Chairman of the Chemical Engineering Society told me long ago that traditional black powder will not detonate. Smokeless powders and at least one black powder substitute can detonate. A simple test to determine detonation potential is to place a pinch of the questioned powder on a rigid steel platform such as an anvil and strike it squarely with a hammer.

I have witnessed detonation with certain charges of smokeless powder IN CARTRIDGE RIFLES. These involved PARTIALLY filled cases and generally some sort of wadding to push the powder in the rear of the case. The chambers were bulged or ringed, but the actions were weak and the barrel material was relatively soft, such as 1144 or Mach V.

Duplex charges of traditional black and smokeless powder can detonate under limited range of circumstances. Any smokeless powder that contains nitroglycerine can detonate. That pleasant smell of just fired shotshell hulls is nitro. People working extensively around and with nitro could become addicted to it and had to go through withdrawl wearing a nitro patch, he shared.

Regards,
Kevin Tinny

[John Bly]

In the Schuetzen game most rifles are fired with breech seated bullets, that is bullets that are seated into the rifling in front of the cartridge case. Talk on the forums regarding black powder loads that generally give the best accuracy are with about 1/8" air gap between the powder and the bullet. They use a wad to hold the powder in place in the case. Wads are not used in smokeless loads with more air gap as it can result in a ringed chamber. This is the same effect as not seating a bullet on the powder in a muzzle loader where the bullet acts as a bore obstruction.

Most black powder cartridge shooters have gone to Swiss powder as they believe it leaves a softer fouling. Some have gone to the Old Eyensford by Goex. Very few shoot straight Goex 2F or 3F.

[Maillemaker]

On the issue of fouling, I have recently started experimenting with paper patched bullets of the British Enfield style.

I am using the same old Goex powder I always use.

The reduction in fouling is amazing. When I run a patch down the barrel after shooting 10 or so rounds the patch comes out only with a slight greenish tinge. I suspect the lubricated paper is acting like a cleaning patch and is cleaning the barrel on loading and firing.

Steve

[jonk]

Well the schutzen guys with their breech seated bullets is another issue too, proving the point; they are doing by design what we are discussing here.

I would strongly challenge the idea that black powder doesn't detonate and smokeless does. I HAVE personally tried the hammer test (few kernels of said powder on a steel anvil, hitting it with both steel and brass mallets). MY results indicate that NONE of it detonates. The only time it went off was with steel on steel contact, and I suspect a small spark was to blame; brass on steel did exactly nothing. These tests were hardly exhaustive, but it is the principle at least behind why brass drums are used in bp measures (which I also think is overkill).

But back to the fouling question: WITH A GOOD LUBE (and that means one that works well in your gun) while in principle I notice more fouling with lower pressure charges, it doesn't really matter. I can shoot my Hoyt barrel 1 shot or 50 shots without cleaning, and the 50th goes down as easy as the first, and clean up is about the same either way, in terms of time and patches. More time spent on the outside of the nipple of course, with the fouling there.

[Kevin Tinny]

Hello, Jonk:

Thanks for taking time to do your own investigation.

The chemist indicated that in his testing, steel to steel does not contribute sparks BEFORE the DETONATION OCCURS. Most brass isn't hard enough for the test. Certain AMPCO bronze might be, but 35,000 psi red brass, so commonly used, not hard enough.

If you wish, please consider this test with "Pyrodex" GRANULES, NOT the PELLETS.

I didn't intend to get off-track from the main issue of fouling until the widey held misconception that traditional black powder detonates during loading or shooting arose.

Regards,
Kevin Tinny

[Gary Van Kauwenbergh, 101]

This is an interesting thread. I’m not expert, but here are a couple of my observations -
1. On empty space in cartridges: Back in my Army days I was in an artillery unit. Our gun crews would seat the projectiles into the breech until the rotating bands on the round met with the rifling of the chamber. The amount of space in the chamber was always the same, regardless of how much powder you put behind it. One powder charges was made up of a series of bags that were a smaller diameter than the bore, and how many bags you put in the breech depended on how far you needed to shoot. The point is there was always space between the projectile and the powder, and much empty space varied depending the size of the powder charge. I’m not convinced a reasonable amount of space in a cartridge is bad, but I can imagine shooting really small squib loads could give inconsistent ignition.
2. On compressed loads: Testing with my 44-40 Henry convinced me that partially compressed loads are bad. Once you start compressing, group sizes get larger, and they don’t shrink back down until you’ve completely compressed the entire charge inside cartridge, essentially turning the charge into a powder pellet. Below are my notes. You start compressing your powder after about 28 grains, and don’t fully compress the charge until you get almost 34 grains into the cartridge.


Your results may vary.
3714

[Maillemaker]

I love data!

Steve

[Don Dixon]

Regarding air space between the powder charge and the bullet in muzzle loading, black powder fireams:

During the period immediately prior to the Civil War a number of arms were deliberately designed to have an air space betwwen the powder and the bullet because military testing had indicated that such firearms shot better than those using a compressed load of powder with the bullet sitting directly on top of the powder. Some examples:

The Austrio-Hungarian Army's (k.k. Army) Muster 1844 and 1849 Kammerbüchsen used a chamber or patent breech in which the internal diameter of the breech was less than the diameter of the bore. A standard powder charge did not fill up the entire breech chamber. So, there was an air space between the powder and the bullet, which sat on the upper lip of the chamber section.

The k.k. Army Muster 1854 Dornstutzen had a Dorn/Tige pin in the breech. Again the standard powder charge did not fill the breech up to the top of the Dorn, leaving an air gap. The Dorn was no longer used as an anvil to expand the bullet, but as a device to avoid compression of the powder and to ensure the existance of the air gap. As a result, the Dornstutzen was regarded at the time as one of the most accurate military firearms in the world.

The breech chamber of the Swiss Muster 1851 Federal Carbine also produced an air gap between the powder charge and the bullet with a standard charge of powder. The Muster 1851 was probably the most accurate muzzle loading general service military rifle ever built. Dutch military testing indicated that it was fully competitive with the Whitworth, and the German Shooting Union adopted it in the 1860s as the first 300 meter competitive standard rifle.

All of the above were made in the thousands and none of them blew up as a result of the air gap, illustrating the point that black powder does not detonate, even with an air gap.

Regards,
Don Dixon
2881V

[Jim_Burgess_2078V]

I've been shooting my Shiloh Sharps carbine since 1978 using a plastic tube to seat my ringtail bullet in the chamber throat and then dump 50 grains of loose FFG behind the bullet. Those 50 grains do not fill up the chamber so there is air space in the chamber when I close the breech and fire. That air space has never been a problem except when weak caps are used and poor ignition results. Carbine is still going strong after 37 years.

Getting back to the original thread, I agree that more powder = greater pressure = a more efficient burn and less fouling. Any fouling, however, can be mitigated by a good fitting bullet and good lube. I used to shoot silhouette matches with a reduced smokeless load (20 grains of SR4759) in a 45-70 trapdoor. The mild load left a lot of unburned powder granules in the bore but that was chased out by the next shot and accuracy never diminished. A also see more fouling and unburnt powder when using light loads in my trap shotguns but that has no impact on my scores.

Jim Burgess
15th Conn. Vol. Inf.

[Cannonman1]

Jim,
Are you familiar with the Garrett Sharps system insofar as breech seal?? I am getting one shortly and was wondering if there is a special tool required to remove the barrel component to clean it??
When shooting my Shiloh, I just keep a nasal spray bottle filled with water mixed antifreeze and every 3rd shot give it a little dose.. It just keeps everything working nicely. Heavy loads?? Interesting point and I expect that is correct. More powder, more pressure, more seal and less fouling. I usually use FFg Goex and shoot 70 grains which seems to work fine. I also keep a wooden dowel with a strip linen soaked in antifreeze to periodically run through the barrel from the breech. Best antifreeze is that used for RV's .. non toxic.

Bill

[Jim_Burgess_2078V]

Bill,

I know that the Garrett Sharps has a removable chamber sleeve like the originals but I have no experience with it. My Sharps carbine and rifle are Shilohs and seal off gas leakage with the breech block plate alone. I suspect you would have to remove and clean the chamber sleeve after every match to keep it functional. Before putting it back in I would coat it with anti-seize grease. (Shotgun choke tube lube is what I use on my cone threads to keep them from getting stuck.)

Jim Burgess
15th CVI