Breech face fouling trouble

[Dphar1950]

There is a lot of very poor advice here on breaching and vent liners. First off the threads will not seal and there will be fouling back 3 threads or more if the breech plug does not seal against a shoulder. I also make my own vent liner and seat them against a shoulder as well. The hole into the bore is large enough to pass powder into the counter bore of the vent liner and that hole is right at the breech face but does not open the threads to the powder gases. The counter bored hole is tapped 12-32.

Below is a plug final fit into a 50 cal smooth rifle barreL. The blue show its seated against the shoulder and is just touching the breech end of the barrel. I will machine the tang later.

If its not installed properly, and this was breeched by the barrel maker. You end up with foiling/solvent/oil traps like this. Isn’t this delightful? Grooving the breech face does about the same thing.

This is going In a 58 cal rifle. If you look close you can see the print of the grooves on the blue used to fit the plug. Yes it has a cupped breech. They give better velocity and cause no problems. Regardless of what people might think here.

Bore scope shows it looks like this installed. The vent is set into the cup so that the vent can be where it needs to be for the rifle design Without shortening the barrel. And yes this was done “back in the day”. The vent liner is also shouldered so all threads are sealed. The vent liner in this case must be removed before removing the breech plug. My 50 caliber heavy match rifle is done this way and is completely reliable and easy to clean IF the person knows how to clean a ML.

 

[Dphar1950]

Originals. Some were also very sloppily breeched.
AND we must understand the modern, interchangeable parts world to get a handle on this. Most taps are set up for about .005” thread clearance. Thats why they leak powder gases and in some case oil lest standing in the bore gain actually follow the threads and get into the stock.
Now the old time makers. In most cases the screw plate and the tap were a matched pair. The tap very likely made the screw plate or the plate made the tap. So there is minimal thread clearance and sometime there was no counter bore. Then simple tapped the bore. Made the plug long enough to Fill the threads to the end and there was a pretty good seal.
This might also apply to “patent” breeches especially in shotguns where the bore was routinely just tapped since the barrel walls are too thing to make the tapped hole larger than the bore.
If the powder fouling is not well flushed from the barrel its possible to get a layer of fouling left in the breech. If this is “dried” and then oiled then the process repeated the fouling, with its oil soaked in will turn to something akin to asphaltic concrete due to the heat and pressure of subsequent firings and can build to a pretty impressive level sometimes. Not common but it DOES happen. I started building MLs over 50 years ago and made mistakes early on in my ignorance. But disassembling some guns that had seen a lot of use taught me things.

 

[Robby]

Dan, I agree with your premise, I do not agree with your conclusions and how it leaks. My threads are sealed, I have disassembled more than one, there is no fouling beyond the depth of the dish and have proven this, it has no where to go.
I do respect your knowledge and experience.
Robby

 

[Robby]

You would be wrong to think I don't research and weigh these things out. I once had a fellow bring me a rifle with a barrel he had rung about six inches up from the breech, even after assurance from multiple respected people that the barrel was still safe I replaced it because I believe that maybe long after I am gone it might eventually weaken and fail. I rebored and refilled a barrel for a fellow that had let it get pitted, a long and dirty job, again, I felt that down the road it would become a hazard and made it into a .52 caliber, actually improving the accuracy, by the way.
There is a well respected maker, that will not use a touch hole liner despite the fact that hundreds of thousands are in use, there are makers, yourself included I believe, that will not use 12L14 with probably millions out there in use and multiple tests done on them. I don't have the latest machinery, my guns are hand made, hand fitted and safe.
Robby

 

[Dphar1950]

I don’t think the combined output of Douglas and the other American ML barrel makers would reach a million. Might but I doubt it. I know the guns from Italy are European spec gun barrel steel. But the completed guns have to go through the gov’t proofhouse. There is a post from some years back on the ALR site by a noted barrel maker (now passed) who told of turning blanks before profiling octagonal and if the encountered a crack, making an interrupted cut “thump” and it cleaned up in the turning They would use teh blank anyway. A friend of mine who started building in the 1950s when I told him of this stated “what about the cracks that did not show up?” Douglas quit making ML barrels due to failures. They initially tried to anneal the cold drawn bars to make them more ductile but finally just stopped all together. T-C had a rash of failures before they changed barrel suppliers (or started making their own) and material and started button rifling them. Button rifling puts an extreme stress on the steel but requires a normalizing process to relieve the stress or the bores will change diameter when profiled. I have seen ”Stress proof” (1144 cold rolled free machining) fail when buttoned when rebated to 1 1/4” to fit in a gun drill. Several in fact. They would split from the start of the rebate to the muzzle. The buttons were pulled from the breech. Blanks made of hot rolled gun barrel quality did not fail in this manner. Nor does testing prove anything. All the barrels in made from a bar of leaded screw stock might be fine and one failure prone due to the inclusions caused by the added sulfur, lead and phosphorus which is never evenly distributed. 12L14 is a brittle steel all cold rolled steels are intentionally since is allows faster feed rates in machine tools. The lead, sulfur and phosphorus act as lubricants. They can be so brittle that when cutting threads the tops of V threads will actually chip off. Brittle steels do not react well to shock loading and firearms shock load the barrel. Shock can cause them to fail at very low pressure. Explaining how a steel with a tensile strength number well over 100K can fail at 20K or less. There was a long series of articles in the old Buckskin Report magazine in the 1970s about barrel steels. started by a now retired metallurgist who specialized in failure analysis. He is also a ML shooter/builder. The only reason barrel makers get away with using this cheap mill run steel is because of the Handloader defense. Faulty science saved TC once. But the plaintiffs lawyer was not wise enough to tests run on out of the can goex. Which in testing by another friend of mine a couple of years later proved that in the test used Goex would give the “smokeless” result as well. People who missed these missed a lot. I have a couple of very nice rifles downstairs that I don‘t shoot anymore. Finally at the pressure levels developed by BP its impossible to burst a 1137 or 4140/4150 series hot rolled, Gun Barrel quality barrel. 1137 will easily stand 50000 PSI with no issues (in lab tests of brass suppository rifles) and 4140/4150 will likely stand 100K. The brittleness of the cold rolled steels is a major factor in the problem. Do you remember the Remington shotgun fiasco when they started using 1144M (M for ”modified”) steel? 1144 WORKHARDENS. Its plenty strong in theory and in hot rolled form is not terribly brittle. But shotgun barrels flex every shot and several trap shooters were maimed when the barrels workhardened tp the point they would no longer flex. Then there is the letter printed in the Buckskin Report from LaSalle steel stating that a whole list of steels they made at the time were not recommended for gun barrels and yeah 12L14 was there. They actually developed the alloy as “Fatigue Proof” which it isn’t of course.

 

[Dphar1950]

And don’t tell me about hand made. I started out making guns on my mothers dining room table.
I don’t care what steel people have in their barrels but it needs to be more informed choice than someone saying in testing they don’t fail. This is meaningless when they have failed in service. But its not something that is talked about much and you SURE will not see it in magazines since the barrel makers buy advertising. Everyone just figures the guy loaded it wrong when in reality it should no burst in any event. I am not particularly concerned about how people breech barrels or install vent liners. BTW the barrel maker I mentioned also made some guns. He posted that he had one come back when the vent liner almost blew out (the lock kept it in). Had he bothered to proof the barre this would not have been an issue in the finished rifle. Had it not been held in by the lock it might have killed someone. Now is that not a confidence builder when you know he or his progeny may have breeched the barrel The guy beside you at a match is shooting. BTW the breech plug with all the fouling? That’s who made and breeched it. The guy that stocked the gun had dovetailed it so deep in the waist I replaced the thing with a Green Mountain. Anytime human life is at risk by a failure the standards are much higher than if its something like a garden hose leaking.

 

[M. De Land]

I don’t think the combined output of Douglas and the other American ML barrel makers would reach a million. Might but I doubt it. I know the guns from Italy are European spec gun barrel steel. But the completed guns have to go through the gov’t proofhouse. There is a post from some years back on the ALR site by a noted barrel maker (now passed) who told of turning blanks before profiling octagonal and if the encountered a crack, making an interrupted cut “thump” and it cleaned up in the turning They would use teh blank anyway. A friend of mine who started building in the 1950s when I told him of this stated “what about the cracks that did not show up?” Douglas quit making ML barrels due to failures. They initially tried to anneal the cold drawn bars to make them more ductile but finally just stopped all together. T-C had a rash of failures before they changed barrel suppliers (or started making their own) and material and started button rifling them. Button rifling puts an extreme stress on the steel but requires a normalizing process to relieve the stress or the bores will change diameter when profiled. I have seen ”Stress proof” (1144 cold rolled free machining) fail when buttoned when rebated to 1 1/4” to fit in a gun drill. Several in fact. They would split from the start of the rebate to the muzzle. The buttons were pulled from the breech. Blanks made of hot rolled gun barrel quality did not fail in this manner. Nor does testing prove anything. All the barrels in made from a bar of leaded screw stock might be fine and one failure prone due to the inclusions caused by the added sulfur, lead and phosphorus which is never evenly distributed. 12L14 is a brittle steel all cold rolled steels are intentionally since is allows faster feed rates in machine tools. The lead, sulfur and phosphorus act as lubricants. They can be so brittle that when cutting threads the tops of V threads will actually chip off. Brittle steels do not react well to shock loading and firearms shock load the barrel. Shock can cause them to fail at very low pressure. Explaining how a steel with a tensile strength number well over 100K can fail at 20K or less. There was a long series of articles in the old Buckskin Report magazine in the 1970s about barrel steels. started by a now retired metallurgist who specialized in failure analysis. He is also a ML shooter/builder. The only reason barrel makers get away with using this cheap mill run steel is because of the Handloader defense. Faulty science saved TC once. But the plaintiffs lawyer was not wise enough to tests run on out of the can goex. Which in testing by another friend of mine a couple of years later proved that in the test used Goex would give the “smokeless” result as well. People who missed these missed a lot. I have a couple of very nice rifles downstairs that I don‘t shoot anymore. Finally at the pressure levels developed by BP its impossible to burst a 1137 or 4140/4150 series hot rolled, Gun Barrel quality barrel. 1137 will easily stand 50000 PSI with no issues (in lab tests of brass suppository rifles) and 4140/4150 will likely stand 100K. The brittleness of the cold rolled steels is a major factor in the problem. Do you remember the Remington shotgun fiasco when they started using 1144M (M for ”modified”) steel? 1144 WORKHARDENS. Its plenty strong in theory and in hot rolled form is not terribly brittle. But shotgun barrels flex every shot and several trap shooters were maimed when the barrels workhardened tp the point they would no longer flex. Then there is the letter printed in the Buckskin Report from LaSalle steel stating that a whole list of steels they made at the time were not recommended for gun barrels and yeah 12L14 was there. They actually developed the alloy as “Fatigue Proof” which it isn’t of course.

 

[M. De Land]

Thank you , I concur with all you have said right down to the barrel steel used in muzzle loaders.

 

[flntlokr]

I shoot .75,.58 , .45, and .40. I have often used the same gun at rendezvous for several days without thorough cleaning until the end. Never experienced any kind of accumulation on any breech face. I lube and clean with detergent and water, use a squirt of G96 for protectant. The only reason for such fouling that I can think of is that there is some petroleum-based stuff in there tfrom patching or storage/cleaning that is turning to tar. This probably doesn't help you much; but it shouldn't be happening. Something is haywire.

 

[bud in pa]

I am not a metallurgist, but I have often wondered how a wrought iron barrel with a forge welded seam could last so long? How about Damascus shotgun barrels which were twisted around a mandril and then somehow forge welded together. Today critical parts that are welded are x-rayed to make sure that there are no porosity holes in the weld. how did they assure a solid forge weld back then? There have been discussions about the merits of DOM barrels vs 12L14 barrels. I personally have no qualms of using Dom barrels . I don't have carved in stone opinions as I don't have the knowledge or experience to have such an opinion.

 

[M. De Land]

I am not a metallurgist, but I have often wondered how a wrought iron barrel with a forge welded seam could last so long? How about Damascus shotgun barrels which were twisted around a mandril and then somehow forge welded together. Today critical parts that are welded are x-rayed to make sure that there are no porosity holes in the weld. how did they assure a solid forge weld back then? There have been discussions about the merits of DOM barrels vs 12L14 barrels. I personally have no qualms of using Dom barrels . I don't have carved in stone opinions as I don't have the knowledge or experience to have such an opinion.

I don't believe you will ever find an honest metallurgist that will recommend 12L14 alloy for gun barrel steel. It will not handle shock load well at any temperature but it gets worse as the mercury drops. I saw and posted pictures on here of one that came apart this winter from a short started ball. That would not happen in a Green River barrel which is constructed of 1134 carbon steel which is very similar to what our high pressure military barrels were made of in WW2 which were 10 series steels "carbon steel" with traces of maganeze , silicone and phosphorus added. Later on NIckel was added.

 

[M. De Land]

I shoot .75,.58 , .45, and .40. I have often used the same gun at rendezvous for several days without thorough cleaning until the end. Never experienced any kind of accumulation on any breech face. I lube and clean with detergent and water, use a squirt of G96 for protectant. The only reason for such fouling that I can think of is that there is some petroleum-based stuff in there tfrom patching or storage/cleaning that is turning to tar. This probably doesn't help you much; but it shouldn't be happening. Something is haywire.

I can't figure this one out yet either as my underhammer percussion gun has the same barrel , breech plug and the nipple orifice is a bit farther away from the breech face and it does not load up and cover the nipple vent. I clean them both the same way with hot water and dish soap followed by W-D 40 to absorb any water in the groove corners. I dry wipe the W-D out and then run a wet patch with Gunzilla in the bore to protect it. The percussion gun does not foul out the vent but the flint gun does, cleaned with the same procedure.

 

[M. De Land]

I think I'm going to try some 2F and see how that does in the .45 cal barrel.

 

[Joemolf]

I have been shooting my flintlock for 4 years now and have had this happen only once in that time. I think it is strictly a matter of atmospheric conditions that promote a heavier fouling.

Agree and with that the powder say Schutzen vice Swiss Caviar. Recently purchased some Schutzen 3F after running out of Swiss; dang after the second shot out of a 45 that typically runs for a dozen or more shots i had to hang on the range rod to get the ball to seat. I also noticed how the fouling was significantly closer to the muzzle. That is some dirty burning powder.

 

[Grenadier1758]

I can't figure this one out yet either as my underhammer percussion gun has the same barrel , breech plug and the nipple orifice is a bit farther away from the breech face and it does not load up and cover the nipple vent. I clean them both the same way with hot water and dish soap followed by W-D 40 to absorb any water in the groove corners. I dry wipe the W-D out and then run a wet patch with Gunzilla in the bore to protect it. The percussion gun does not foul out the vent but the flint gun does, cleaned with the same procedure.

Makes perfect sense to me. The underhammer percussion gun is delivering a jet of heat and flame from the burning percussion primer. That jet of flame will blast through the build up of fouling at the breech in ways that the wave of heat from a pan flash can not.

 

[Dphar1950]

GOOD iron is a better ML barrel material than some modern alloys. Remember that all the Sprinfield Rifle Musket barrels were skelip welded ”best” iron. The short skelp was welded and then run between rollers with a mandrel to bring them the length and shape. They were then proved with 280 gr of musket powder and a 500 gr minie spaced two inches off the powder. If a barrel failed proof a committee would determine who made the mistake and the worker had to pay for the barrel.

 

[Dphar1950]

Agree and with that the powder say Schutzen vice Swiss Caviar. Recently purchased some Schutzen 3F after running out of Swiss; dang after the second shot out of a 45 that typically runs for a dozen or more shots i had to hang on the range rod to get the ball to seat. I also noticed how the fouling was significantly closer to the muzzle. That is some dirty burning powder.

My Nock Breech flintlock will not function with Schuetzen, it forms flakes of fouling in the bore which come loose and fall over the passage from the antechamber and keep powder away from the vent have then prime the vent to get the rifle to fire. Never a problem with Swiss.

 

[Ray-Vigo]

I also agree that one way to reduce fouling generally is to go from Goex or Schuetzen Powder to Swiss. I have one small bore rifle and one small bore pistol that become difficult with fouling, and using Swiss with them has proven helpful. It does not eliminate the problem entirely, but it certainly reduces it. My larger bore rifles and muskets are less picky.

 

[Dphar1950]

I don't believe you will ever find an honest metallurgist that will recommend 12L14 alloy for gun barrel steel. It will not handle shock load well at any temperature but it gets worse as the mercury drops. I saw and posted pictures on here of one that came apart this winter from a short started ball. That would not happen in a Green River barrel which is constructed of 1134 carbon steel which is very similar to what our high pressure military barrels were made of in WW2 which were 10 series steels "carbon steel" with traces of maganeze , silicone and phosphorus added. Later on NIckel was added.

Actually the military has used 4150 since it was developed, Simply because it can he shot at very high temperatures with out failing. I think you will find the information in Hatcher’s book of the Garand. I have shot barrels till they were incandescent and have seen others done the same. Back when I ate a lot of C-Rations and slept in the mud. The 45 ACP pistol barrels were, SFAIK made of mild steel. And at least some civilian barres still were at least until the stainless craze took over.

 

[M. De Land]

I don't believe you will ever find an honest metallurgist that will recommend 12L14 alloy for gun barrel steel. It will not handle shock load well at any temperature but it gets worse as the mercury drops. I saw and posted pictures on here of one that came apart this winter from a short started ball. That would not happen in a Green River barrel which is constructed of 1134 carbon steel which is very similar to what our high pressure military barrels were made of in WW2 which were 10 series steels "carbon steel" with traces of maganeze , silicone and phosphorus added. Later on NIckel was added.

I made two errors in this post, the alloy Green Mtn uses (not Green River) is 1137 not 1134 which I keep flubbing for some reason. The first digit means carbon steel, the second digit mean carbon is the chief alloying agent and the last two digits are the percent in hundreds of carbon used in the alloy (.37 ) not 37 percent. This is one of the few companies that actually uses gun barrel certified steel and is the reason they are all I use. The barrels are also very uniformly bored, reamed and I think single point cut rifled, as I check them with a scope and plug gauges.