When will it blow up?

[tark]

Wow, my old post, brought back to life. I'm still shooting my shooter grade broom handle, and it is nearing the 5000 round total. Almost all of that has been Tokarev ammo, simply because it has been more available, and cheaper, at least until recently.

I have replaced springs on my gun and I will do so again soon. Any gun will beat itself to death if you shoot it with old springs.

Every time I ask someone how they know that Tok ammo is loaded hotter than Mauser ammo I get the same answer. "I read it in" you choose the publication. Or "I have been reading it for years, it must be true." Again, I must implore you to do a little research. Find a forty year old copy of "Cartridges of the World" The Mauser round generated 1410 FPS. The Tokarev; 1390. This was determined by chronographing the military loads of that time period. The Mauser has a one inch longer barrel, which would account for the difference. Looks like the same load to me. There was simply no reason for the Russians to load it hotter. And they didn't.

And let's put to rest that myth of Submachine gun ammo in 7.62X25. Go read JohnnyCs posts. Look at his credentials. I think he knows what he is talking about. No such animal exists.

Now, modern 7.62X25 is loaded to a much higher velocity than the stuff forty years ago. But it is not loaded to higher pressures, just more velocity. Advances in modern propellants.

In closing I will direct you to Lyman's 49th edition reloading manual. The 7.63 and the 7.62X25 are listed as interchangeable. Both are covered under the same reloading data.

time to go shoot my broomie some more

 

[Jim K]

FWIW, the reports (rumors) I have seen about "Czech ammo" did not involve S&B commercial ammo, but "Czech military ammo" of unspecified type, usually described as "hot submachinegun ammo". Again, why would any nation deliberately issue ammo that it knew would blow up its own or its allies' guns? Doesn't make a lot of sense to me.

Jim

 

[Slamfire]

FWIW, the reports (rumors) I have seen about "Czech ammo" did not involve S&B commercial ammo, but "Czech military ammo" of unspecified type, usually described as "hot submachinegun ammo". Again, why would any nation deliberately issue ammo that it knew would blow up its own or its allies' guns? Doesn't make a lot of sense to me.

They don't deliberately make over pressure ammunition. But as ammunition ages, the pressures rise as the gunpowder deteriorates. As gunpowder ages performance deteriorates then you get safety problems. Old gunpowder, past its shelf life, the pressures rise. The powder grain deteriorates unevenly which causes "burn rate instability". Some powder breaks down into a dust, and that will spike the pressure curve, just look at coal dust explosions for an education of what dust will do. Double based powders, the nitroglycerine wicks to the surface, and that will spike pressures, and double based powder have less than half the shelf life of plain nitrocellulose.

Nitrocellulose the grain deteriorates unevenly, the burn rate changes unevenly, pressures always rise, and then the ignorant call it "submachine ammo".

What makes anyone think that the surplus ammunition on the market is somehow good as new?. The original owner, Armies, paid someone to go through the stuff and sort out the ammunition that was turning bad. You come on by, trade your cow for what is purported as magic beans, but guess what, there is no pot of gold or magic harp at the end of this story. The seller laughed his way to the bank, because he made money on ammunition that would have cost him to demill.

As for the blow ups with new ammunition, I think the pistol was at fault. It looks as though the sidewalls of the ammunition ruptured. I think that was inadequate case head support. Just look for Glock issues about 10 years ago. Lots of Glocks blowing case heads because of inadequate case head support. Lots of pictures too.

 

[giggitygiggity]

It would be awesome if we could see a reinvigoration of the 7.62x25 round and perhaps a modern handgun or SMG chambered for it!

 

[earplug]

I enjoyed this thread

Broom Handles are a bit of awesome firearm history.
Norinco could sell some reproductions to people like me.

 

[Jim K]

Maybe some powder deteriorates and becomes dangerous, but I have had several batches of ammo that failed to fire or fired only the primer and when broken down showed the powder turned to, well, powder. The residue could not be ignited with a match. SOME ammunition might become dangerous from high pressures as it ages, but I am not sure a flat "always" statement to that effect can be made.

Jim

 

[Slamfire]

Maybe some powder deteriorates and becomes dangerous, but I have had several batches of ammo that failed to fire or fired only the primer and when broken down showed the powder turned to, well, powder. The residue could not be ignited with a match. SOME ammunition might become dangerous from high pressures as it ages, but I am not sure a flat "always" statement to that effect can be made.

Lucky you. If you keep on shooting ammunition that old you will blow up your firearm. A person only has so much luck, when it runs out, you will have plenty of time for regrets. Always is a strong word, and it is sometimes wrong. You would expect that falling out of an airplane at 33,000 feet without a parachute would always result in death, well someone survived. http://en.wikipedia.org/wiki/Vesna_Vulović Does not mean I am going to leap into the unknown at altitude. Break stick, disc or ball powder down into a talc, you have vastly increased the surface area. If that burns, the pressure curve will be very high. I don't know why your breakdown powder did not ignite, maybe you could have loaded the stuff with a new, fresh primer and been able to get it to ignite. I do have accounts of guns blown up with ammunition that the gunpowder turned to dust, or clumps.

 

[Jim K]

Hi, Slamfire,

In reading your posts I have pretty well concluded that every gun you touch blows up, and that every round of ammo you ever saw was a small bomb. If I were you, I would give up shooting and take up a less hazardous hobby or business.

Jim

 

[sequins]

Do not criticize someone for caution. Perhaps he is less tolerant of risk than you are. Afterall, many of us carry guns because we are less tolerant of risk than the general unarmed public.

I don't fire antiques personally. I had a scary experience with an 1872 Lefever side by side. I was young and foolish and fired modern 2 3/4th shells through damascus barrels just totally ignorant of the grave risk. I am glad I'm still here typing on gun forums and now I'm so scared I'd leave an unissued garand where it lies and only fire production weapons.

 

[superc_1]

Regarding OP wishing to see pictures of a blown Mauser C96, it took a little hunting, but I found this one.

http://forums.gunboards.com/showthread.php?352511-Broken-Broomhandle-part-1

What I find most interesting about the failure is the bolt lock held, it is the upper receiver/barrel extension that just ripped apart. Micro fissures or crystallization? Who knows?

 

[joem1945]

Anyone that wants to shoot 7.62X25 in their C96, go ahead, it's your gun. For me I reload for my C96 with just enough powder to make it operate. Why beat a classic old gun to death?

 

[tark]

Superc 1 thank you for the link, that is the only picture I have ever seen of a blown up Broomie. I notice the bolt stop didn't fail, the barrel extension did! I also noticed that it did not fail from shooting 7.62X25 ammo in it. It was trashed by the ammo it was supposed to be shooting! Weak springs probably played a part in it. It's age may have also factored in. Was it an early gun? Metallurgy advanced a lot during the 30+ years of production. My gun was made in the early thirties.

Joem1945, if your broomhandle functions with lighter loads, it has weak springs in it. If I try to shoot my broomhandle with anything other than gonads to the room divider loads, it short strokes and stove pipes. Try this simple test:

Push the barrel of your gun against a hard surface until the barrel extension moves back and unlocks the bolt. While holding it there, move the bolt backward about a tenth of an inch. There should be spring pressure on the bolt, which increases the further you pull the bolt backward. All too often, you can pull the bolt back slightly and it will stay there, a bit out of battery. That gun has a wasted spring, will usually function with weak loads just fine, but it is beating itself to death. Pull the spring out of your bolt. If it is shorter than four inches it needs replacement. Wolff will sell you an extra strength replacement for a few bucks.

Broomhandles are no different than any other automatic pistol in one respect: They function best with full power loads.

 

[Jim K]

Mausers can and have blown up, but the subject of this thread was whether military ammunition issued for the Tokarev or the CZ-52 will do it. The pistol shown in the link provided by Superc is interesting but not relevant.

First, the ammo was not Russian, Czech or German military issue ammo, but U.S. commercial.

Second the blowup appears to have been caused not by high pressure ammo but by a stuck forward firing pin, perhaps caused by improper reassembly of the pistol. The stuck firing pin caused the gun to fire out of battery and the result is as we see it. I very much doubt that either the ammunition or the age of the pistol was a factor.

Jim

 

[acme_labs]

This is wholly unscientific, but I fired some PPU Serbian 7.63 Mauser through a CZ-52, and it was noticeably quieter than the Romanian 22 81 headstamp. NOTICEABLY. Just my .02.

 

[Jim K]

As usual this thread has strayed badly. The issue is NOT whether some ammo might in some way become higher pressure over time. Nor is it whether some ammunition is hotter than others or whether some company loaded some ammo too hot.

The question is whether a national military ISSUED to its troops, deliberately and intentionally, ammunition intended for one class of guns (SMG's) that could be loaded and fired in another class of weapons (pistols) in use by the same national army at the same time and would destroy or damage those weapons and injure troops.. If anyone can demonstrate that that was done, the personnel responsible should have been charged with treason.

Jim

 

[tark]

I'm with you, Jim. I'm still skeptical that "Submachine Gun" ammo ever really existed. There is no reason for such ammo to exist, and a number of reasons why it should not. What if you load your subgun with pistol ammo? OOps! It might not function, getting you killed. Blowing up your pistol with subgun ammo will produce the same thing.

The whole concept is just ridiculous.

 

[Monac]

Maybe it started with the Italians? Their Glisenti and Brixia pistols used a cartridge that was externally identical to 9mm Parabellum, but was significantly less powerful, because those pistols could not handle full power 9mm. Later, in the 1930's, the Italian Army began using Beretta submachine guns chambered for 9mm Parabellum--but the Glisenti rounds were still around too, because the Italians were too poor too ever re-equip completely. That would have created a low-power pistol round and a (relatively) high power submachine gun round, identical in appearance and physically interchangeable.

Hey, at least it's a good story, isn't it?

 

[acme_labs]

So, all of that said, what causes the bending of the rear of the barrel extension, where the bolt stop is, weak springs, flame throwing loads, Voodoo, bad Chinese luck?

 

[barnbwt]

Weak springs, dangerous overpressure ammo (handloads or powder degradation), and/or incompetent Chinese manufacture. Also bad karma.

"I'm still skeptical that "Submachine Gun" ammo ever really existed"
Now, if Tok had seen the development and deployment of 9mm, this probably wouldn't be the case. 9mm has been used in so many guns by so many people for so many missions, its statistically impossible for there not to have been some uber-hot load issued for one reason or another (I recall the Uzi's had a rather hot loading, as well as Swedish K's). But since, what, half a dozen guns of any type were ever made for Tokarev, and only about as many nations (USSR bloc being one) ever adopted it, and there is no official record of the SMG loadings, I think it's pretty cut and dry.

Seeing how most of the surplus stuff was made, I think "SMG only" loads would primarily result in SMGs with case necks broken off inside the chamber, as opposed to blown up pistols. Another reason it was never hot rodded like that (at least not with staked bullets).

The real question is; is there a market for a hot-rodded Tokarev round unsafe to fire in surplus pistols? A 30-cal going 5.7 speeds from a short barrel could be pretty cool, is all I'm sayin'...

TCB

 

[acme_labs]

So, shooting the old blue box S&B 7.63 mauser may be a job for a CZ52, or just pull and repowder?

 

[tark]

Let's just blame all blowups on George Bush. Along with every other bad thing that ever happened.

Sorry, off topic.

I think the cracking and deformation of the barrel extension on that blown up broomhandle started and ended with weak springs. The gun was firing ammo made for it. Firing out of battery is going to blow out the case head and spew a lot of gas into the action but I don't think it is going to fling the bolt rearward with any extra velocity.

The barrel extension on the gun is softer than the bolt stop. This is by design. In the event of a catastrophic failure you get what you see in the picture, and notice the bolt DID NOT LEAVE THE GUN! When I hear stories of sheared bolt stops and bolts flying rearward I am extremely skeptical, because that situation is as close to literally impossible as you can get.

When a hardened metal piece, and a softer metal containment structure are subjected to extreme stresses, the softer metal is going to give. It will peen, stretch, crack and eventually give, which is what happened in the pics. It will not maintain its structural integrity while the hardened piece shears. The hardened piece will beat the softer structure to the point of deformation , but it will almost never shear off. Of course, it the hardened piece was improperly hardened and was too hard it could shear but that is what hardness testing and proof testing are for.

I check my broomhandles' barrel extension for signs of trouble often. I even had it magnifluxed earlier this year to check for any cracks too small to see. There were none.

I'll keep shooting Tokarev ammo in it.