Black powder pressures

[keith44]

I have been told by many people who are otherwise very intelligent that it is not possible to overload a BP weapon of any type when loaded with real BP.  Many years of research later I know the truth, and came across some interesting trivia.  So what say you how much pressure can BP develop and what can your gun safely handle?  Not accurately, but absolute max before something gives way.  (this is a test)

[Nobade]

It is pretty hard to blow up a cartridge gun or revolver with black powder, since the space is limited. Not so for muzzle loaders, and it's not hard to destroy one if you really want to.

[Ranch13]

There's a ton of pressure data around, the Lyman Blackpowder Handbook is an excellent source.
Goex has cartridge pressure data on their web (or did at one time)
 Sam Fadala did some interesting experiments trying to blow up a modern muzzleloader, with no real spectacular results.
 In the 1878 winchester catalog there's some interesting reading in the 1876 section where they decided to put some guncranks writings to bed about how weak the 76 action was, they finally bulged it but it was a massive overload that took up about half the barrel.
 Yes you can turn about anything into a pipe bomb, but sooner or later Darwins theory will kick in.

[keith44]

hmmm, 50% voted the correct answer.  Admittedly I worded the question vaguely, but still this stuff was used for blasting and mining for years until the advent of dynamite.
 

[StrawHat]

It is pretty hard to blow up a cartridge gun or revolver with black powder, since the space is limited. Not so for muzzle loaders, and it's not hard to destroy one if you really want to.

Not really, Elmer Keith blew up several Colt Model P revolvers in 45 long Colt before switching to the 44 Special cartridge in the same revolver.  He was able to write about it and parley his experiences into a nice career.  He also was able to write about a few of the rifles he wrecked using black powder. 
 
 

[Ranch13]

 Elmer wasn't shooting bp when he blew up that gun up.

[coyotejoe]

Absolutely not, he was running heavy smokeless loads in a blackpowder Colt revolver.
No doubt it is possible to blow up a traditional muzzleloader with BP but it would require a ridiculous charge to get there. In Lyman's testing they limited pressure to 15,000 CUP and to reach that required lots of powder, like 160 grains of 3f under a .50 caliber ball and that is no where near to bursting a good barrel. 
I have never heard of a muzzleloader being blown up except with smokeless powder. There is a photo circulated of an Indian made Brown Bess with a split barrel but no one seems to know much about it so far as the exact load and circumstances of the blow up.

[keith44]

19th Century British experimenters conducted tests with black powder and recorded pressures in excess of 100,000 psi.  Results verified by the navy.
 
 

[coyotejoe]

Yes, in a closed bomb, not in a firearm.

[keith44]

A slight over charge, with a fouled barrel and too tight of a projectile short seated tryinr to get off a second shot at game, and you just made a bomb.  There are to my knowledge no american made muzzleloaders that are proof tested.  This was simply an effort to call attention to the fact that just because you're shooting real black powder does not mean you can load it any way you choose and be safe.

[Ranch13]

A slight over charge, with a fouled barrel and too tight of a projectile short seated tryinr to get off a second shot at game, and you just made a bomb. 

 I don't hardly think that's right at all. If you slide a projectile down the barrel and got it even close to the powder charge, you might ring the barrel, but the simple act of loading the projectile is going to clean alot of the fouling out from the muzzle down.
 Sam Fadala and Lyman have tested and tested and retested tremendous powder charges and multiple balls and such in an effort to blow muzzleloader barrels and they have bulged a few but never turned one into a bomb.
 Even in the Winchester 1876 tests they had something on the order of 2500 grs of powder and a handfull of Martini bullets in that barrel and only managed to bulge the reciever.
 To make a bomb you would have to solidly plug both ends and not allow for anyway for the gases to excape except to split the material it was contained in.
 There may be some cheap Spanish and Brazilian made muzzleloaders from the 60's and early 70's that could be made to come apart , but there again it would be someone rushing the threshold of Darwins theory.

[keith44]

Since that was taken from the Lyman manual I suggest you re-read it.  Only a suggestion, you are free to do as you will.  But remember 90% or more of the front stuffers in use in the USA have not been proof tested in anyway.

[Ranch13]

 Actually I suspect most of the muzzleloaders are proofed before they go out the door, with the liability issues being what they are, nobody is going to turn loose an unknown.
  You might also want to check out the tests the Val Forgett of Navy Arms and George Nonte did back when Navy started selling their muzzleloaders..
 Ever read any of the stuff Turner Kirkland used to put in the back of the Dixie catalogs?
 
 

[keith44]

 Ever read any of the stuff Turner Kirkland used to put in the back of the Dixie catalogs?
 

Yup, what part?
 

Actually I suspect most of the muzzleloaders are proofed before they go out the door, with the liability issues being what they are, nobody is going to turn loose an unknown.
 

Nope, Savage tests to 60Kpsi, Navy Arms imports most of their line, from europe where everything is proofed. Muzzleloaders proofed to 28Kpsi in Europe.  The rest do not bear proof marks, no marks, no test.
 
Remember muzzleloaders are largely unregulated by ATF, and the courts will go after a user prior to a company with an army of lawyers on retainer.
 
 
 

[coyotejoe]

There is a theory that proof testing doesn't accomplish anything, that fireing a high pressure overload may just stress a barrel enough that it will later let go with a normal load.
 I have several times absent mindedly short started a ball without ramming it down before firing it and the rifle suffered no damage what ever, just a very heavy fouling residue. That was with mild target loads but never the less it isn't the disaster waiting to happen as you make it seem, but if you're afraid of your rifle then just hang it on the wall.
And by the way, what does the ATF have to do with anything? They have nothing to do with proof testing, if they did that they wouldn't have time to run guns to Mexico.

[coyotejoe]

http://www.mansfieldnewsjournal.com/article/20110720/NEWS01/107200327/Shiloh-man-loses-appeal-exploding-gun-case?odyssey=tab|topnews|text|Frontpage
 
That is a link to a typical muzzleloading "blow up", smokeless powder of course. I've heard of nipple drums and vent liners being blown out, probably because of damaged threads, and I've heard of cap & ball revolvers chain firing, but I've never heard of any reasonably well constructed muzzleloader actually blowing up with blackpowder.
 I know of a stupid drunk who poured a new T/C Hawken barrel 1/4 full of powder and stuffed another 1/4 of the barrel with well tamped grass. He fired it from the hip and the gun survived unharmed. Stupid shooter however lost lots of skin from his right hand when recoil drove the hammer and trigger guard back through his hands and lots of skin from his left hand where the rear sight caught it. He earned a new camp name that day, "El Stupido".

[keith44]

I still stand by the intent of the post.  Know what you are doing, load the gun inaccordance to the manufacturers recomendations, and never assume you know better

[StrawHat]

Elmer wasn't shooting bp when he blew up that gun up.

Sorry for the elay in respinding, it took me a while to find the reference.  In "Sixguns by Keith" (1955, Bonanza Books) on page 129, Elmer Keith wrote the following;
 

 
I believe he also recounted that particular incident to "The American Rifleman" in one of the first of his published articles for that magazine.  As I recall, he stated it was the first of several such mishaps that caused him to seek a smaller cartridge that would still allow him to obtain the ballistics he wanted in a hunting cartridge and led him to the 44 Special.
 
(13 Aug, I was able to sharpen the copy a bit)
 
 

[keith44]

Way to go "Straw" worth the wait.

[Ranch13]

Notice he said it was caused by a "weak case"?

[coyotejoe]

Probably so. Elmer was working with balloon head brass, modern brass won't hold 40 grains of BP. When fired with BP brass will become pitted and brittle if not washed out promptly. I seem to recall reading somewhere that shortly after introduction it was decided that 40 grains was too much for the Colt revolver and factory loads were reduced to 35 grains. The Army concluded that the original load produced too much recoil for the average trooper and adopted the Smith & Wesson load of a 230 grain bullet and 28 grains of powder. That is the load the army wanted to duplicate with the .45 ACP.

[keith44]

I remember the 28 grain load being used to tame recoil, and the duplication of that for the .45 acp.  The other I hadn't heard before.

[Nobade]

It's not the black powder, it is the mercury fulminate in the primers. Once they switched to chlorate primers the brass quit falling apart.

[keith44]

and yet the powder when confined can develop pressures sufficient to move mountains
 

[Ranch13]

and yet the powder when confined can develop pressures sufficient to move mountains

Yes it can, but it takes a whale of a lot more to move a mountain than you can stuff in a cartridge case, or what any reasonably thinking being with opposable thumbs , can push into a muzzle loader.