how flat is flat-nose for tube mag?

[muskeg13]

Here's part of the Army accident report that was filed because I lost several workdays. If you still choose to believe it can't happen, that's your choice.

The gentleman who wrote the articles in Rifle Magazine also sent me a long letter in which he explained that while several factors in my case may or may not have led to the accident itself, they definitely contributed to the severity of the damage.

These factors were: sensitive pistol primers (Federal Large Pistol); fast burning powder (10 gr of Unique); and a short fat straight .44 Mag case that takes up most of the room inside of the magazine tube and aligns the cartridges in-perfectly nose to tail. All these combined led to a bad accident, and if any one of these had been different, there probably wouldn't have been a catastrophic failure of the magazine tube.

A less sensitive pistol primer or rifle primer may not have gone off in the first place, or if so, there may not have been a chain reaction where all 6 primers ignited. A slower burning powder may not have produced enough gas and energy to cause a chain reaction, but the first case might have split and the powder only partially burned. Like you can see in Charlie Sometimes' photos, if the cases had been bottlenecked or were longer rimmed cases they wouldn't be aligned with the nose right against the primer, but would have been slightly offset. Finally, if there had been more room in the magazine tube (not taken up by fat straight sided cartriges), there would have been more room for the gas to expand and vent, without blowing the tube apart.

[tall grass]

muskeg13

You know I wouldn't think that you were doing anything wrong loading the 44 the way you did but it sure makes me think, after seeing you account, that I need to be more careful what I use for powder and primers. Sure sorry that you were hurt.

Regards

Jim

[Charlie Sometimes]

I don't think that all the gas from that many cartridges could be handled by anything! They don't vent them except at the back where they are loaded!

I'd say that the sensitive, or soft primers were the real issue. The boolits conformed enough under recoil to deform and detonate the primers. If there were more in the tube before this happened, and you got off a few shots, then it couldn't happen until there was enough room for the recoil to effect the rounds still in the magazine, because of spring tension- IMHO.

Muskeg13- your pictures are amazing! There is a lot of information to be gleaned from the "autopsy" of the pictures and the shrapnel- I'm glad you survived! Look at the headstamps on the boolit noses! WOW! And look where the tube failed- most magazine tubes are welded seam, so it could have failed anywhere along the length, but it didn't. It failed at the action- if I am seeing what I think I am seeing, right? Under the forearm.

You're right handed, the cartridges exploded, the tube failed, and allowed the magazine plug to hit you in the left cheek, propeled by the additonal force of the explosions, etc. Ouch! Happened so fast all you could say was- "Wha.....".

[muskeg13]

I didn't have time to say anything.

The mag tube backed out of/was blown out of the receiver and flared out so that cartridge fragments and the magazine plug were directed towards my face. On the Rossi M92, the mag tube fits into a recess in the receiver, but is neither pinned or is screwed in place. Even so, there was so much pressure inside of the mag tube that the muzzle end screw was sheared and the cap and the spring were propelled downrange to the front, never to be recovered.

Parts of two cartridges, including the highly compressed one in the photo, ended up lodged under the carrier. The loading gate was blown outwards to the right, and of course, the forearm was shattered.

I had been shooting from sandbags at the bench and was sitting in an old style military metal chair with arms. The explosion knocked me back in the chair, but I remained sitting upright (taking the full force in the face). It all happened in an instant, and I remained conscious the whole time. I was worried about going into shock because I was on the range by myself on a Sunday afternoon. Fortunately, the bleeding stopped quickly and since there was nerve damage, there was little pain. After policing up gear and locking the range, I was able to drive myself 10 miles into town and get stitched back together by the local doc, who did an excellent job. All things considered, I was quite lucky the injuries weren't worse.

The magazine plug had done the most damage, knocking a hole in my cheek, splitting my lip and knocking out a front tooth. The next day, I found the plug 25 yards behind the bench. There were also numerous small wounds caused by cartridge case fragments. Most of these were only superficial, but could have easily blinded me if I had not been wearing glasses. Several bullets left nasty bruises on my left forearm. In addition to glasses, I credit wearing a heavy sweatshirt over a flannel shirt, a baseball cap and ear muff protection to minimizing the injuries.

[Charlie Sometimes]

WOW! WOW! WOW!

I'm glad you made it, and you kept your wits- I think that is a key to not going into shock, especially being alone on the range. That is a good reason to always take somone with you, though.

I've had a few things happen to me on different occasions, that left the people around me less than able to help me after suffering injury. I had to help myself, and then help them- and they weren't even injured. All they did was SEE my injuries.

Remaining CALM, COOL, and COLLECTED was never better advice- you have got to be able to THINK under pressure in serious situations.

GLAD YOU SURVIVED!

[Charlie Sometimes]

You know, it might be a good idea if manufacturers would drill holes (sort of like a fine sieve) in magazine tubes (located, facing downward, under the forearm where dirt and water couldn't easily get in) that would vent pressure in a situation like that.
That might have directed some of it away, instead of forward and backward like it did- it wouldn't take much to do.

[muskeg13]

You know, it might be a good idea if manufacturers would drill holes (sort of like a fine sieve) in magazine tubes (located, facing downward, under the forearm where dirt and water couldn't easily get in) that would vent pressure in a situation like that.
That might have directed some of it away, instead of forward and backward like it did- it wouldn't take much to do.

This may be the best advice/idea I've ever gleaned from the internet!! Thank you! I'm going to modify all of my tube mag levers, because I'd like to continue shooting them and can't afford to suffer another mishap. I could cover the "vents" with electrical tape to prevent moisture and debris from entering the tube. Vents covered by the forearm will still work to prevent serious bodily injury. A splintered forearm won't kill me. I'm proof of that.

[59sharps]

Think again.

interesting bottom right photo primer looks like it has a fireing pin hit whats up w/ that

[muskeg13]

That's the indentation caused by the primer anvil of the cartridge ahead of it. Look at the cartridge above it in the photo. The mark in the center of the primer is actually a little bump sticking up, and the bump is the primer anvil.

[Charlie Sometimes]

That could be the reverse impression of the primer anvil. Lighting plays havoc with seeing elevated or depressed areas on surfaces.

I don't think you'd have to worry about debris under your forearm, or any getting under your magazine tube. Any forearms that I have ever removed from a rifle shows that is one of the cleanest spots on a rifle.

If you drill, drill lots of small holes so the follower doesn't hang up anywhere. After you drill holes, don't forget to polish the burrs from the inside of the tube away. A long dowel split on the end with wet/dry and light oil for a slurry would work, I'd think. The tape wouldn't be a bad idea, but after the adhesive gets old and fails, it will collect dirt- so I wouldn't do it, unless you change annually.
I would also vent the forearm along the sides of the barrel so that any escaping pressure in the future would vent up and around the tube and barrel, for what little it might be worth. Usually, there is sufficient gap under the forearms of most to help so there wouldn't be much to remove.

BUT, let's PRAY that this NEVER happens to you again.

[sagacious]

Muskeg13,
Thank you for your very informative commentary and photos. I'm very glad to hear that you weren't more seriously injured.

Do you happen to recall what the approximate alloy was that the bullets were cast from? Although it would likely have seemed counterintuitive before viewing your photos, one now imagines that softer lead might pose a greater hazard than hard lead in the case of wide-meplat bullets. Do you consider the lead alloy hardness/softness to be a factor in the chain-fire?

[muskeg13]

They were 200 gr commercially cast bullets, but were advertized as being softer alloy than normal, for black powder cowboy action shooting. Using a Saeco lead hardness tester, they registered a 7, or 12 on the Brinell scale, which is about the same as 1:20 alloy. I don't know if lead hardness was a factor, except that these bullets were not that hard or particularly soft either. I had loaded 8 rounds initially, and the accident occurred on the second shot, so I find it hard to believe the bullet noses had been battered by recoil to the point they would set a primer off, but who knows?

[w30wcf]

muskeg13,

Very sorry to hear of your mag tube explosion. Thank you for sharing your story. Glad that you weren't more seriously injured. The only other documented .44 Mag tube explosion that I know of was with someone using full patched round nosed bullets.....not a good idea!

Any chance that some of the rounds might have had primers that were not quite flush?

w30wcf

[J Miller]

muskeg13,

I'm also glad your injuries were not more severe. w30wcf asked about the possibility of a high primer so I won't duplicate his question.

I do have a thought about bullet shapes though. Many of the supposedly "flat nose" bullets are actually convex. They have a slight point rather than being flat. Did those bullets you used have such a shape?

I have shot bullets with such a convex noses in my in my 45 Colt lever guns and it concerns me. That slight point could set right up against the primer in front of it. The clear tube pics actually verify this. And if there was a slightly high primer, the combination might be the cause of the magazine KABOOM.


Joe

[Charlie Sometimes]

I do have a thought about bullet shapes though. Many of the supposedly "flat nose" bullets are actually convex. They have a slight point rather than being flat.
I have shot bullets with such a convex noses in my in my 45 Colt lever guns and it concerns me. That slight point could set right up against the primer in front of it. The clear tube pics actually verify this. And if there was a slightly high primer, the combination might be the cause of the magazine KABOOM.

I mentioned the possibility of a high primer, too, but I forgot about the convex noses! I have noticed them on a lot of the Lee molds that I have. The wider meplats aren't as prominent, but there none the less. I'd say the manufacturers do that to help ease the removal of the boolit after casting, but you are correct in that it could pose an unrecognized issue.

Put both together, and Bang!- at the wrong time!

[Retro]

Several years ago there was a write up in Rifle or Handloader magazine

This one's from Gun Digest

http://www.retro.co.za/gundex/articl...re%20Safe.html

[rob45]

... I forgot about the convex noses! I have noticed them on a lot of the Lee molds that I have. The wider meplats aren't as prominate, but there none the less. I'd say the manufactureres do that to help ease the removal of the boolit after casting,

You are correct. Matter of fact, if you look at the "Custom Bullet Mold Design Assistance Sheet" from Lee, they show it on the sample drawing. Their example shows a 3 degree rearward taper from the center of the meplat. They also state next to it- "(not necessary, but allows for easier bullet release from mold)".

If you have a copy of Modern Reloading, 2nd edition, go to page 169. It's right there.

That is based on their custom order recommendations; now, the question is, do they do it on regular production molds?

May or may not make a difference. If you do the calculations, that slight of a taper would only make a difference with a primer that was seated flush or higher.
I think this is probably why all primer manufacturers recommend seating .004" below flush.

The jury will always be out on the possibility and exact causes of magazine detonations, and I personally take every precaution I can.
I like smooth actions and triggers, but I do not lighten the hammer fall so much that I have to start using sensitive primers. I also uniform the primer pockets on a regular basis so that the primers seat below flush. And naturally I like wide meplats on my bullets.

But as has been shown here, things can happen no matter how small the likelihood of it. I'm just glad muskeg13 is OK.

[Charlie Sometimes]

That is based on their custom order recommendations; now, the question is, do they do it on regular production molds?
If you do the calculations, that slight of a taper would only make a difference with a primer that was seated flush or higher.
I think this is probably why all primer manufacturers recommend seating .004" below flush.

Yes, I think they do it on regular production molds- out of the 4 molds that I have of Lee manufacture that are designed with RF noses, only 1 does not have the taper. It is a custom 6 cavity Big Lube mold.
On the Lee C452-300-RF it flattens out visibly before reaching the edge of the meplat- more questions there. I've used them plenty in my tubes with no problems, but I do like you- make sure the primers are flushed or recessed 0.004"

[muskeg13]

No on convex noses. As far as I can remember, they had perfectly flat noses. As for the possibility of a high primer, given what happened, all I can say for certain is that I can't say absolutely that there wasn't one. I primed each case with a Lee Hand Priming tool, that had always given me good results with more than flush seating, and I usually check each round with my finger for flush-ness, but??? There's always the possibility that a bad one slipped through. The moral to the story is, if in doubt, recheck the whole lot again.

I have recently noticed that one of my 2 Lee Priming Tools (the one set up for large diameter primers) is not consistently seating primers deep enough. I have to fully seat these primers using the priming arm of my press. Doing this, primers are always seated below flush.

[Charlie Sometimes]

I also noticed on my boolits that the 200 grain meplat was smaller than the others, but it is flat and not convex.
I use a RCBS handing priming tool on all of my primer seating, and occasionally, I notice a few cases that require extra pressure to get a fully seated primer.
I use a single stage press to load all of my ammo- I fill all the case with powder, look at all to see if the level appears to be the same, and once bullets are seated and loaded nose first into the box, I look at those primer again, just in case.
I've never had the experience that you had, and I HOPE I NEVER DO!