After the fact, I found I used the wrong primers.

[hightime]

I've loaded so much 45 Colt this last year, I made the mistake of using LP primers instead of LR. in my 45-70. My loads shot well. What could have happened? Just incomplete or slow inition? I did this with 40 rounds. All shot very well.
I know, I'd better use a better brain at the reloading bench.

Owen

[Leverdude]

Only real danger or issue is the fireing pin might not reach them good. LR primers are taller than LP primers so Rifle primer pockets are deeper. In really hot loads it might matter since the primer is going to get pushed forward until it bottoms out & then upon fireing the pressure will push it out against the bolt face.

[Don McDowell]

Worst case scenario, some might say would be a bit of peening of the breechblock around the firing pin hole,due to the flow of the supposedly softer and shorter primer cup. I've shot thousands of bp loaded rounds in my 45-70's and to date have not noticed any ill affect. I don't imagine there'ld be much trouble with smokeless loads held to "trapdoor" levels either. Pressure levels between trapdoor loads and higher end handgun rounds isn't that much.
Doing that in a high pressure number like a 308 ,243 etc might have a different outcome, probably pierce some primers.

[Dewight]

I use large pistol primers in both my 45-70 and 38-55. They are mid-power loads I use for lever action rifle silhouette.

[hightime]

I shot them all off without a problem. I found a load I loved. I hope my accuracy will still be as good with rifle primers.

Owen

[Old Savage]

The load that did this used pistol primers. The rifle had been converted to 450 Alaskan. It appeared that the bullet had been kicked a couple inches down the barrel then the main charge ignited blowing the barrel and peeling it back and blowing the receiver.

[mikld]

O.S.,
OUCH, I bet that smarts! Loose any fingers? What was the load used with this Kaboom?

[hightime]

I'll either get my brain adjusted or give up reloading. Maybe I wasn't in a big danger, maybe I was, but not having my thoughts together isn't going to work.

Owen

[Booger Bill]

Golly! Do you have a hook now?

[Charles]

The Marlin does not have an excess of steel over the chamber due to the receiver. I see by the photos, the chamber split in two and took the top of the receiver with it.

The 450 Alaskan was developed for the Winchester 71, which has much more barrel meat around the chamber. The 450 Alaskan has a powder capacity greater than the 458 Winchester Magnum and can operate at pressure, well beyond Marlin strength. IMHO, the Marlin is not a suitable firearm to be converted to the 450 Alaskan round.

[Old Savage]

Gunsmith Jack Huntington agrees with you and would not do those conversions on the Marlin but --- it was the barrel that ruptured first and peeled back.

[Old Savage]

Mikld - I talked to the fellow who blew this one up - an Air Force major - and saw his hand the way they sewed it back together. He had fired many of this load before this happened. Appears as mentioned that the bullet had been kicked a few inches down the barrel then the main part of the charge went off.

Here is another picture

[2571]

Bought my scoutmaster's loading room from his estate when he died at 85. Had reloads dated 1968 through the year before he passed.

Older he got, the more inconsistent his charges got. Pulled down all the stuff made in the last 25 years. Some of his recent .44Mag stuff was so hot, I am sure it would have ruined a pistol.

Fortunately, he was on a FIFO system with shooting his reloads.

[earlmck]

Appears as mentioned that the bullet had been kicked a few inches down the barrel then the main part of the charge went off.

Great (and scary!) pictures there, O.S. Had to be some tremendous pressure to rupture the barrel like that.

I looked real hard for what it was that made the folks figure that the bullet went down the barrel a ways and then the powder went off and she ruptured. I can't see anything in your picture, and it is a real fine picture. Don't you suspect it would have more likely been caused by a double charge of a fast powder? Anyway it would be interesting to know what his loads were. (This coming from a fellow who has intentionally used more than a few pistol primers in his rifle loads...)

[Old Savage]

The load was well known to the investigators. There was evidence in the barrel that does not show up in the pictures. Here this is maybe better. Notice where the blackened area is in the barrel and where it becomes shiny. Now look where the tube is bent and ruptured. This was not an explosion in the chamber. It happened forward of that. He had fired many rounds of this load and kept careful records.



My guess and it is just that, is that there may have been something like a piece of tumbling media in the flash hole that restricted full ignition initially then it the full firing of the powder occurred in the barrel and chamber mouth not at the place in the rear where the metal is thinnest in the receiver. If you look at the center point between the blackened area and the base of the inside of the case it appears that is where the rupture occurred and blew backward splitting the barrel also.

We have seen others of these from time to time and there always seems to be various speculation theories.

This may offer other clues and it won't hurt my feelings if you come to a different conclusion.



Point is it did happen. These don't seem to blow with the full power loads of 4198 published by Hodgdon's.

[earlmck]

Point is it did happen. These don't seem to blow with the full power loads of 4198 published by Hodgdon's.

It sure happened and we aren't likely to know for sure why, but the simplest explanation would be double charge. A double charge of 4198 at full power won't fit in the case (and would ignite just fine with pistol primers). But say he was using 20 grains of Unique with the 405 grain bullet for a very pleasant 1400 fps load, and under 30K psi (I'm playing around in "QuickLoad" for these suppositions). A little "ooops" happens and he throws a double charge of 40 grains Unique (fits easy -- still only 90% full). But this produces over 90K psi which would make things come unglued. Same deal with a very common 30 grains 5744 charge. 60 grains of 5744 is still only 95% full, gives over 80K psi.

And I can see what you are saying about where possibly the detonation originated a bit forward of the chamber, too. So maybe the "blow forward, stop, detonate" explanation is correct. Just sayin' -- I tend to like the simplest explanation as being the most probable.

So I guess I would be interested in the load data. If he was using something like my Unique or 5744 suppositions I'd sure lean that way. If he was using a light load of something slower that still filled the case well over half-way, or maybe a ball powder like 748, well then I'd be thinking "maybe those pistol primers did do the bad thing".

Anyway, thanks for sharing this, O.S. Great pictures there. Sure makes a fellow think, doesn't it?

"Ale, man. Ale's the stuff to drink...
For fellows whom it hurts to think" (A.E. Housman) ... Well, guess I'll have another...

[AJMD429]

I shot them all off without a problem. I found a load I loved. I hope my accuracy will still be as good with rifle primers.

That in itself will be an interesting question.

It appeared that the bullet had been kicked a couple inches down the barrel then the main charge ignited blowing the barrel and peeling it back and blowing the receiver.

I've always wondered why that IS a problem; if the main body of the powder ignites after the bullet is down the barrel, the volume if the containment is much greater, so I would think that would actually lower the peak pressure. Plus, at that point the bullet is moving down the rifling, and once moving, engraved, and probably has a hot jacket, I'd expect the friction to be pretty low.

Is it just a much faster burn rate, or maybe a 'detonation' instead...?

(I also don't fully understand the difference, but once read that if the burn progresses through the material faster than the speed of sound, it 'detonate' vs. 'burns'...?)

If it really was due to a pistol primer being used instead of a rifle one, then - what would happen if you got one sort of 'lame' rifle primer...? Surely out of the hundreds of thousands of primers we all fire off, some aren't consistent...

[Old Savage]

Well Earl, as is the case for the simplest solution in an odd situation .. looks like something is true. The powder was 322 and not a hot load. Seems there had been a couple other odd ignitions prior to it blowing up. He had read on the internet that using match grade pistol primetd would gove better accuracy.

[Don McDowell]

Seems there had been a couple other odd ignitions prior to it blowing up

Were all the prior bullets accounted for in the target? I'm leaning more towards a squib left a bullet in the barrel. Bore obstructions will blow the hell out of things from time to time.

[earlmck]

The powder was 322 and not a hot load. Seems there had been a couple other odd ignitions prior to it blowing up. He had read on the internet that using match grade pistol primer would give better accuracy.

OK, that blows my supposition out of the water. So he'd have had an almost full case of a medium burn-range extruded powder. I could well have been the fellow on the internet telling him he might get superior accuracy using a match pistol primer. So be warned... pay no attention to anything Earl says! He knows not of what he speaks!

I'm leaning more towards a squib left a bullet in the barrel.

Yeah, that would have been my next guess, though I would not have expected a squib from that load. But we already know what my guesses are worth!

the volume if the containment is much greater, so I would think that would actually lower the peak pressure. Plus, at that point the bullet is moving down the rifling, and once moving, engraved, and probably has a hot jacket, I'd expect the friction to be pretty low.

Exactly. That's why I was looking for some other explanation -- that "bullet start - stop - boom" just doesn't seem to work in my computer.

[Old Savage]

Isn't that the mechanism for Secondary Explosion Effect? S.E.E.

Here is one description:

http://lutz-moeller-jagd.de/English/Detonation.htm

Although so-called S.E.E. was very difficult to repeat "in the laboratory", (one frustrated researcher even doubted it existed !), a popular theory advanced was that the primer flashed over the surface of the powder only igniting part of it. This created just enough pressure to force the bullet forward into the forcing cone of the bore where friction brought it to a temporary halt. Milliseconds later, the entire charge is ignited but the lodged bullet is unable to accelerate forward quickly enough to release the rapidly developing beach pressure. One writer referred to this as the Double Ignition Theory.

RWS in 1983 refer also to too weak an initialisation of the powder as also being a possible cause. This might be the case if the primer were contaminated with oil, if it were seated too deep in the primer pocket or if the firing pin did not strike it sufficiently hard due to a weak spring or damaged tip. More recent observations on this problem note that the surviving shooters recall hearing a snap sound, then the big boom as in "Ka...Boom". It is postulated that the incomplete ignition that followed the (for whatever reason) too weak primer spark, led to a temporary deflagration or short smouldering phase. Milliseconds later, the now mainly gaseous state of the charge is a much more perfect explosive medium, unlike the carefully retarded powder granules it replaced. So when it goes Boom, an extremely high pressure spike blows the gun apart.

My understanding of what the fellow experienced with the other loads was a delayed ignition and not a squib with no power. The loads he was using with the 322 would not have been lacking of recoil so that you wouldn't notice it.

Do a bit of a search on this and you will find other discussions with folks on all sides of the case.

[2571]

. . . Seems there had been a couple other odd ignitions prior to it blowing up.

Very telling.

I'm surprised this experienced shooter did not abandon that batch of reloading until they could be explained.

Did anyone examine the unused portion of that reloading session?

[Old Savage]

Yes.

[Don McDowell]

Thing is if he was using enough 322 to get significant recoil, then there should of been enough of it in the case that a flashover wouldn't of happened.
It is surprising that after reporting 2 hangfires, he didn't stop and try and figure out why...

[Old Savage]

He is an Air Force major what can you say. And, reading about these things, the conditions seem to odd enough to not make sense. Many gravitate toward the simplest explanations as Earl mentioned but that doesn't explain some. I recall Sixgun and his 1886 with 5744.

And regarding the shooter - he couldn't wait to build another one.

[2571]

He is an Air Force major what can you say. And, reading about these things, the conditions seem to odd enough to not make sense. Many gravitate toward the simplest explanations as Earl mentioned but that doesn't explain some. I recall Sixgun and his 1886 with 5744.

And regarding the shooter - he couldn't wait to build another one.

I'm embarassed. Did any ofd us enquire if the shooter is ok now? Did he regain full range of motion in his hand?

[Old Savage]

They sewed his hands up and he showed it to me. It was good enough to be drinking a beer at a banquet. He did not appear to have any obvious deficit and wanted to get back to shooting this kind of rifle and maybe something bigger.