Breech failure

[D. Taylor Sapergia]

I'm posting this with trepidation but hope that it will serve to help someone down the road.
This rifle was returned to me yesterday from Kansas, which is a frustration in itself.  The problem in this two year old rifle is that the breech was leaking gases downward, and burned a cavity in the stock under the barrel adjacent to the junction of the plug and the barrel.  Apparently its being going on for some time as the cavity is of considerable size and depth. 
What has happened is that the thread journal was too thin where the metal was drilled out to connect the cone with the nipple.  The drill bit was too large, or passed too close to the face of the plug.  The photo describes it better than I can.  You can see in one picture where the gases have carved out a bit of the plug itself.
There are a couple of positive things here.  No one was injured.  The fault is neither the maker's (me) or the shooter's...just a flawed plug.  And finally, the fix is easy - all I need to do is fit a new plug.  The threads are not damaged by erosion or rust, and thankfully, the old plug was fitted up tight at the end of the journal and against the end of the barrel.  Otherwise, I hate to think what might have happened.
There's one more thing.  Against our advice, the owner shoots whatever he can buy at Walleyworld - Pyrodex, Triple 7, whatever.  These "powders" are very corrosive, and his barrel is toast.  In the second to last picture, you can see the pitting in the clean .40 cal GM barrel.  Frustrating.

[rich pierce]

I'd understand you may not want to name a component maker, but was that the old Sharon breech or something else? 

How would a maker test a breech to avoid this sort of thing happening?  Anything short of magnafluxing?

It can and does make a builder crazy to see the things some gun owners will (and won't) do to a gun.  We all have horror stories.  However, this gun still looks great, excepting the corrosion.

[Mike Brooks]

The subs are corrosive. I pitted my repro henry barrel with APP. I thought I had it clean, when I picked it up to shoot it again several weeks later it was a rust bucket. VERY aggravating.
Looks like you fix won't be too bad, just have to match the finish.

[Acer Saccharum]

Thanks for posting that, Taylor. I suspect the metal was extremely thin to begin with, and that acidic fouling did the rest. Those plugs are real hard to clean.

That's why a flat breech flint poses the least worries: it's so simple.

T

[D. Taylor Sapergia]

The breech was just one of two (two barrels) I bought from TOW for this build.  Short of having an x ray done with a series of pictures, I cannot see how one could foresee this sort of failure.  In this case, I did not enlarge the hole or chase the threads down to the bottom of the journal, as I sometimes do.  The first plug I put into Daryl's beloved 14 gauge rifle developed little vents in the top, from a faulty casting, but that's now only two failures that I know of, in nearly 275 rifles/guns/pistols.
I have to dress the new plug down to the barrel and the tang.  I might get it close, then finish it out of the barrel, and case harden it.  Then I wouldn't have to worry about colour catch, and it would set it apart from the .32 cal barrel.  I'll post pictures of the repair.
Christmas time...it'll be a month getting a new plug from Minnesota.

[D. Taylor Sapergia]

Tom, it's a hooked breech, so it's easy to take it out of the rifle, put it into a bucket of cold water, and flush EVERY LAST BIT OF FOULING out of the plug and barrel.  Real easy.  The harder you hydraulic that water with the down stroke, the better it flushes the plug.  I have a rook rifle from the middle of the 19th century with an almost identical plug, and it still shows the case colours on the inside of the breech plug.
I think the only way to check that thin spot perhaps is to slide a tight fitting drill bit into the hole, and look down from the top to try to eyeball how close the hole is to the corner.  Then it's just a guess and a leap of faith.

[Dr. Tim-Boone]

That's why they call'em "Cussin" guns!!  Dang newfangled stuff!!

[Mad Monk]

Thanks for posting that, Taylor. I suspect the metal was extremely thin to begin with, and that acidic fouling did the rest. Those plugs are real hard to clean.

That's why a flat breech flint poses the least worries: it's so simple.

T

I keep seeing comments regarding acidic fouling as a mechanism of corrosion in "black powder" guns.
The idea being that since BP contains sulfur it produces sulfur-bearing products of combustion that form acid in the bore.

No deal here.  BP fouling is quite caustic.  Any sufur based acid would be quickly neutralized.

The REAL culprit is chloride salts.

Pyrodex is based on 17 parts of potassium perchlorate that is found as potassium chloride after powder combustion.

Keep in mind that military cartridges were corrosive due to the use of a perchlorate, or chlorate, based primer composition.  The main charge of BP or smokeless was not in itself corrosive.  It was the tiny amount of chlorate/perchlorate in the primer.
Compare the two.  Corrosive primers or percussion caps with a fraction of a grain of chlorate or perchlorate.  Compared to a main charge that is 17 parts perchlorate.

GOEX up until 2000 left a corrosive residue.  They used potassium nitrate produced by the Vicksburg Chemical Company.  Bankrupt in 2000.  Vicksburg used potassium chloride converting it to potassium nitrate via a reaction with nitric acid.  The conversion process was not 100% effective so there was always some unreacted residual potassium chloride in the powder.

Chlorides are noted for pit corrosion.  In the gun the pits deepen rapidly from the pressure pulses created during the firing of the gun.
I hasve photos here of a patent breech that did the same thing.  Pits on the inside that quickly deepend and then exited on the bottom of the breech plug.  The gun was stored in a horizontal position.  Had it been stored vertically it would have looked just like the one in the photo.

When Col. Rains operated the Confederate Powder Works he bragged that there were no detectable levels of chlorides in the saltpeter the works purified.  Other powder companies purified their saltpeter to a point where it was impossible to detect any traces of chlorides.

But today that old rule of thumb is ignored by most powder companies.  Those who use the saltpeter produced in Israel have no traces of chlorides.  I have not looked closely at what comes out of Chile these days.

Bill K.

[D. Taylor Sapergia]

Mad Monk:  that is very very informative.  Thanks for taking the time to enlighten us.

[Daryl]

I also know the person who owns that rifle and think he has cleaned it with comercial solvents on the gun.  I saw him clean his other .32 in a hunting camp where he was a client & it appears he knew the proper method of cleaning.  One can only speculate how or how often he cleaned the rifle.

The damage appears to me to be neglect - ie; shooting the gun one day and putting it aside with pyrodex fouling for continuing to hunt or shoot the next day (or week) - over and over again - or most likely, putting the fouled barrel away and forgetting to clean it for an even longer period of time.  In the Mid-West as up here during the summer, you can probably get away with that shooting GOEX 2F or 3F and not hurt the barrel in the least, but his certainly is badly pitted - far past rust - those pits are deep.  I helped Taylor take the picture of the interior of the barrel and it about made me sick just looking at it.

I just checked a deep grooved Bauska barrel chunk that has been sitting fouled (uncleaned since last shot) in my barrel rack of junk for the last 30 years and it would still be shootable with a 4ought 'polish'. There is very, very mild pitting from the 1970's black powder I last used in it before junking the barrel - probably Curtis and Harvey's 3F. In no way does this 30 year neglected barrel look even remotely like the little .40 barrel Taylor photo'd here.

Bill - thanks for the heads-up. I've wondered about pits under pressure before and know we know.   Also, the smaller the bore, the higher the pressure and therefore the faster the pits deepen.

[Dphariss]

I also know the person who owns that rifle and think he has cleaned it with comercial solvents on the gun.  I saw him clean his other .32 in a hunting camp where he was a client & it appears he knew the proper method of cleaning.  One can only speculate how or how often he cleaned the rifle.

The damage appears to me to be neglect - ie; shooting the gun one day and putting it aside with pyrodex fouling for continuing to hunt or shoot the next day - or most likely, putting the fouled barrel away and forgetting to clean it for a longer period of time.  In the Mid-West as up here during the summer, you can probably get away with that shooting GOEX 2F or 3F and not hurt the barrel in the least, but his certainly is badly pitted - far past rust - those pits are deep.  I helped Taylor take the picture of the interior of the barrel and it about made me sick just looking at it.

Bill - thanks for the heads-up. I've wondered about pits under pressure before and know we know.   Also, the smaller the bore, the higher the pressure and therefore the faster the pits deepen.

Its impossible to clean the chlorate fouling as one would BP. It takes very little to get it started.
If he used a water based patch lube it will attack the steel from the water and its cumulative.
Using a water based product on the fouling is POISON. Even Hoppe's #9 will turn the stuff "on".
There was a writeup in Rifle Magazine (or Handloader) some year back in which a guy ran a patch wet with Hoppe's though a 375 H&H he had been shooting P-dex and lead bullets in and then took his wife out for supper. Next am the barrel was toast. Hoppe's has alcohol, alcohol will invariably have some water.
If the stuff is made wet is has to be removed immediately by a complete cleaning.
There were numerous gun shipped back to Shiloh with frosted bores sometimes in just a week or 2 after the owner received it.
The thing is it may not look rusty. It just eats the steel. The barrels often look white rather than rust colored.
One of the websites had a post from a shooter in Germany who had contacted the proof house about P-dex  and they told him is would eat tunnels in the bore. Same thing we are seeing here and I have had reported to me. It gets a start then just keeps making it deeper and deeper like a crawdad hole.

Dan

[rich pierce]

Wow, I had no idea that the substitute stuff was so corrosive.  Thankfully I've never been tempted to use it, but will pass this info on to those who do.

I've often thought that maybe barrels needed to be freshed out so often on the frontier because they were left reloaded after firing.  IIRC, Lewis and Clark needed to fresh out their barrels on the journey.  Maybe if they were using substitutes, they'd have had to fresh them out before they got out of what is currently the state of Missouri.

[Tim Hamblen]

Wow !But again, we've probably all seen this before. Build or give someone a gun, tell them in detail how to care for it and the next time you see it, it's near junk status. Disheartening at the least.My question is, what kind of accuracy was he getting while jumping from powder to powder ? Can't be good. This person would have been better off with a CVA Bobcat from Wally World for $89.

[Acer Saccharum]

Given that the owner knew how to clean, Taylor, I suspect the drilled hole was very close to the edge of the inside corner. The web might be but .002 thick, and look good upon visual inspection, yet blow out slowly under pressure.

The only mechanical way you have is to have drill bit inserted in the hole. Clamp the drill horizontally, then rig up a height gage to put a pointer into the inside corner of the plug. Withdraw the plug, and position the pointer over the drill bit again to see what your gap is.

[Mad Monk]

Wow, I had no idea that the substitute stuff was so corrosive.  Thankfully I've never been tempted to use it, but will pass this info on to those who do.

I've often thought that maybe barrels needed to be freshed out so often on the frontier because they were left reloaded after firing.  IIRC, Lewis and Clark needed to fresh out their barrels on the journey.  Maybe if they were using substitutes, they'd have had to fresh them out before they got out of what is currently the state of Missouri.

Rich,

The freshing out thing had a lot to do with the very soft wrought iron barrels.  Bore walls easily worn by escaping gases.  Plain dead soft wrought iron is fairly corrosion resistant.  While easily erroded by the very hot gases produced by the burning powder.

With the wrought iron and most steel alloys the bore will suffere light surface rusting if the gun is left uncleaned for any length of time at humidity levels up around 50% or higher.
In the late 1800's one noted authority on black powder guns commented that one event of after rusting is equal to a year of shooting when it came to barrel wear.

Bill K.

[Darrin McDonal]

WOW !!!!! That is a really interesting situation. Thanks for this thread. It is very informative and extremely important as we would all agree, for the safty factor.
This site is the best!!!!!!
D. McDonal

[smoke]

I don't want to start an argument but i used 777 and pyrodex when i could not get real BP. Cleaned the barrel with cold water as soon as i got home from the range. No rust yet. So prompt cleaning after shooting must work ok or guns would be exploading all over the country. Correct?

[D. Taylor Sapergia]

Well, to each his own.  This failure is too much of a coincidence to make me feel anything but nervous about substitute powders.  I have around 275 muzzleloaders under my belt and this is the only one where the client (to my knowledge) has gone against my advice and used substitute powders, and this is the only failure like this that I've been made aware of.  be careful.

[Dphariss]

I don't want to start an argument but i used 777 and pyrodex when i could not get real BP. Cleaned the barrel with cold water as soon as i got home from the range. No rust yet. So prompt cleaning after shooting must work ok or guns would be exploading all over the country. Correct?

No offense intended but I have heard this a lot and its seldom true with careful inspection.
I have never seen a barrel shot to any extent with chlorate powders that I could not tell at a glance it was used with such by its appearance.
I heard the "my gun is not pitted" thing back when  I was working at Shiloh.
I was giving a tour or talking to a customer etc.
Told the guy that we did not recommend substitute powders due to corrosion. He told me he had a Ruger OA on the car that he had shot a lot with corrosive powders and had not seen any pitting.
Not only was the gun seriously pitted almost anywhere the fouling had touched, cylinder face was completely covered with pits and craters,  but it had apparently ate the bluing off  (seen this too) since it was blued right over the pitting. Thus I tend to be skeptical. Most shooters will see the early stage pit and not even recognize it for what it is.
Not trying to say you have pitted the gun. I am saying you need to look with magnification to pick up the early stage frosted looking pitting once you know what to look for its pretty easy to pick out.
If you have no pits you are lucky. If you have a problem in progress it will look like tiny craters of the moon under magnification.
Another indication is the increased fouling and difficultly cleaning when BP is subsequently used.
Dan

[smoke]

Hi: Taylor and Dan. I emailed Daryl and he said throw the stuff out and that is what i will do.I am not taking a chance with it. Dan

[Pete Allan]

I just talked to one of my well known dealers and he said he just replaced a drum that the threads were eroaded out from the use of subituite powder. he said all he had to do was to tap out the threads to the next larger size -- 3/8"-24 -- and put it back together. He said the owner always did a very good job of cleaning so the barrel inside looked like new. I bet he changes to real BP.

[P.W.Berkuta]

A while back (5 years or more) I purchased some blank hooked breach plugs and tangs from TOTW on sale. It was understood that they were sold as is and were not X-rayed. After I bored and threaded them I had 5 out of 12 that had visible voids in the castings. I do not know what the other plugs condition were as I did not invest the time or money to have them X-rayed - I ended up throwing them out. I could not take the chance of a latent failure which would lead to a LARGE law suit -- you just don't know what the castings have inside unless they are X-rayed. I now machine my plugs out of billet mild steel and use the cast tangs. One less headache to worry about.