[Greg D.]

I`m not sure if this is in the correct location, so please move if needed.
Has anyone had a less than full powder charge detonation in a round? Here is the story, and no there were no injuries.
Was shooting a match two weeks ago and through the course of fire, one round sent the mag to the ground and smoke everywhere. Didn`t recoil much more than normal, but I knew something was wrong.
The Nowlin barrel looked like Elmer Fudd`s gun when Bug`s sticks his finger in the barrel and Elmer pulls the trigger, except from the chamber end, It just ballooned out and sent pieces through the ejection port and down the mag well. Put the gun away and finished with anoher gun. Got home and took it apart.
The barrel is split down the bottom at the lugs almost full length of the barrel and the slide is stretched out accordingly. Got it off the frame and the barrel out of the slide.
Called Nowlin the next morning and got a call back that afternoon from John Nowlin. He said "send me everything and I`ll take care of it, I want to see what happened." He asked if the barrel was bulged from a prior squib load and no it wasn`t.
Talked to John a few times this week and got a call from him today. Here is what he was told. The Oklahoma crime lab determined that it was a less than full load detonition in the barrel. He outright admitted he has NEVER seen this type of damage.
We discussed this forum and he asked if I would post to see if anyone has either had or seen anything like it.
John has been very helpful and very fair about the repair to my SA pistol, so this is NOT a Nowlin bashing by any means.
Thanks for any replies.

 

[Lycanthrope]

Happens sometimes in rifles. Loading too light will do it with them at times.

What powder?

 

[hjk]

Occurences such as this are one more good reason to have a steel frame gun - particularly a 1911.

 

[sam1963]

Thanks for the info. Did you get any pics?
How does a less than full powder charge cause this much damage?

 

[Greg D.]

Powder was WW 231. Gun was a SA loaded stainless. I have a picture but no way of posting it, sorry.I also don`t know how or why or how much powder caused this, neither did John when we spoke, but he said he is going to find out all he can. If it can happen once then it can and will happen again.

 

[dsk]

If the amount of powder is so low that it exposes the flash hole, when then primer ignites the flash travels across the top of the powder, setting the whole lot off at once instead of the slow, even burn that is normal. What you end up with is a very short but intense pressure spike. This issue is most likely to happen with rifle rounds and long pistol rounds due to the case length.

 

[sam1963]

Thanks for the explanation.

 

[Valkman]

Interesting. What is the difference between what happened here and if a round was shot with a double charge of W231? Would there be alot more damage?

 

[EdGCNM]

If provable, this could be of great interest to the industry. The problem is proving it. Low load detonation is like the holy grail of smokeless powder problems. There have been anecdotal stories -- and I'm not by any means saying untrue stories -- of detonations reported once in a while for over a century. The problem is that despite a lot of effort, no one has been able to duplicate it (called SEE or Secondary Explosion Effect) in the laboratory. If it does in fact occur the conditions under which it happens must be extremely rare. In virtually all reported cases, where the damaged gun and cartridge case were examined scientifically, it's not possible to say whether the damage was caused by detonation of a low load or a double-charge or a barrel obstruction (not necessarily a bullet) instead. Most instances where such an examination was done do not in fact point to detonation as the culprit.

Some experts believe that detonation can only occur with very slow burning rifle powders in large-volume cases with light loads. Others argue that high concentrations of nitroglycerine as found in the fastest powders (like Bullseye) should have the potential for detonation, but again no hard evidence is there to prove it.

Anyway, I'm glad that no one was injured!

 

[Greg D.]

You are correct about the rare instance of this happening. Unfortunately it does occur. John Nowlin said the crime lab peole he had examine it said the presence of unburnt powder in the frame was the indicator of what occured.
As far as what damage this did compared to a double charge, John said they test their barrels to a triple charge load and they will not cause this much damage as my barrel and gun have.

 

[Dave T]

This phenomenon has been around for at least 30 years to my knowledge. Back in the '70s I was involved in PPC shooting (Police Revolver) with bull barreled 38 Specials shooting wadcutter loads. The standard reload in those days was 2.7g of Bullseye behind a 148g full wadcutter seated flush with the case mouth.

Various "rumors" and "stories" were told of this handload occasionally producing a "detonation". The nay-sayers always claimed it was a double charge that no one wanted to admit to. I remember reading an article in (I believe) Police Marksman magazine about someone trying to duplicate the phenomenon but never could. Still the stories of it happening persisted. It was also known among the NRA 2700 shooters who used the same load.

As stated in an earlier post here, this supposedly occurs when a very light charge lies below the flash hole and for some reason "detonates" when the primer goes off. The theory is that the entire charge ignites at once instead of burning progressively as normal.

 

[Sheldonj]

sounds more like a double powder charge to me. I use to shoot compressed powder charges with a TC in .45 long colt with a bull barell. You could get some real wicked velocities, but were quite often spitting out unburned powder.
Or is it possible you had a double wammy one low powder charge and the second an over charge that plowed into the first?
Glad no one was hurt.

 

[MoNsTeR]

Sorry, I don't believe it. 231 is much too fast to detonate.

 

[Greg D.]

Well believe it or not, John Nowlin has the proof of what the result was and he seems to believe what the Crime Lab has told him. I`m certain they have more experience than all here combined. It seems they have ruled out a double charge as I said before they claim a triple charge will not damage the barrel like this and there is no bulge in the barrel were a prior round would have stuck. Like it was said at leat no one was injured.

 

[Stumpy]

Dave T,

The 2.7 or 2.8 Bullseye powder bomb story related to .38 spl. 148gr. wadcutter loads has been around since the late 40's(when I first heard of it)but to the best of my knowledge they had tried for years to duplicate/prove it but I know of nobody ever having done so,I have shot thousands and thousands of rounds of that load along with thousands of other Bull's Eye shooters and I have never seen or heard of an actual instance of it happening to any of the old Bull's Eye shooters,would like to ask anyone on this Forum if they have any info about this load.

Stumpy

 

[dsk]

Gunwriter Mike Veniturino (sp?) did an article once regarding this subject. It was after he had assembled some mild handloads for an old Colt SAA and managed to blow it up. I'd dig up the magazine, but it's deeply buried in a wall of boxes. :hrm:

 

[Stumpy]

Forgot to add..

About the particular pistol in question,was any metallurgical testing done on the barrel of this pistol? other questions,what was the bullet being used in the load? wasn't oversized was it?Magnum,rifle or standard pistol primer? Just curious about the load,I would still like to see a metallurgical analysis of the barrel first and foremost. just a thought.

Stumpy

 

[TiroFijo]

dsk, please try to resurrect that article!
I "think" it was Venturino in sn article in Shotgun News a couple of years ago describing his experiments in large cases (44 spl and up) with very small doses of slow pistol powders (like 2400, H110, AA9, Win296).
I've never heard of a credible (and of course not reproduclible) report of this phenomenon with fast powders like BE or Win231.
But of course you never cease to learn

 

[TAMU94]

Had a similiar issue once with a 357 reduced load in my SW 686. The round produced a big bang with strong recoil. Very high pressure blew out the primer and jammed the cylinder fast. I use a Dillon Square Deal so I'm pretty confident I didn't double charge it (the SD auto-advances with each pull of the handle unlike the 550). Gun was fine.

I used to be skeptical of detonations until this happened to me. I would agree that this is extremely rare. Double charges are far more likely with reloading and are probably 95% of the blown up guns seen on the range (the other 4.95% being "experimenting" and bad recipes).

 

[tex_n_cal]

I vote double charge. Remember that unless you weigh loaded cartridges with a digital scale, it's very hard to find double charges when the charge is so light. If the remainer of the batch of ammo is still available, weight them on an accurate digital scale, and see if you can find any more double charged loads.

The "detonation" of fast burning pistol powders has never been proven in the lab. "detonation" of slow burning rifle powders, when used in reduced charges, in large capacity cases, has been proven in the lab. It's also been proven that double charges of pistol powders do push pressures off the scale.

Off an on I have tried to make extremely light "gallery" loads with .433 dia round balls and Bullseye powder, in the .44 mag. Although I used data from Speer, they were a dog, erratic behavior and velocities, including some squib loads that stuck in the barrel. Never had anything but extremely low pressures, and lots of bad smells from half-burned Bullseye.