Reason for ammo failure? (pictures)

L

lewallen

Inactive
Hello everyone, a few years ago when i was much younger and very foolish i bought a Ruger Mini 14, the person who i bought it from included roughly 400 rounds of ammunition. I was told that the ammunition was bought at a gun show, i didnt really think anything of it. So i went and shot the rifle in the desert without wearing hearing or eye protection ( I know bad idea). After shooting for a while i loaded a new magazine and started shooting, BOOM it felt like the rifle exploded. The magazine was ripped open very voilently, and all of the remaining rounds were dumped on the ground. I only needed to replace the firing pin to get the rifle operational after that. I thank god that i wasn't injured. But that taught me a very good lesson to NEVER shoot without eye or ear protection, and never shoot someone else's reloads. I always wondered what had caused the failure of that round, i found the mangled shell casing. So here are some pictures of the casing on photobucket. Let me know what you guys think may have caused this. (I apologize in advance if i am posting this in the wrong place)

http://s1377.photobucket.com/user/max7701/library/
 
The pics don't show anything worthwhile so its a guess (or two).
Wrong powder.
Double charge of powder.
Out of Battery discharge.
Headspace horribly wrong.

Are the usual suspects though.
 
"...pics don't show anything worthwhile..." Except it might be milsurp. Can't see the head stamp well enough. Don't look like reloads though.
Post some better pictures that clearly show the head stamp. Or just post what it is. Got any unfired left? Pictures of them would help too.
 
Headstamp is Sellier and Bellot. Marked S&B .223 REM. And yes i do believe i have some leftover, i will post pictures as soon as i can
 
An OOBD would cause the case to separate like that. The front (softer) case part would still be expanded & grabbing the walls but the rear (harder) part wouldn't.
BUT!
It would also have to have the bolt unlocked so the case could back up enough to blow out into the mag-well.

I'm leaning towards a major gun problem rather than an ammunition related one.
 
'' I'm leaning towards a major gun problem rather than an ammunition related one.''

Wogpotter could you elaborate on what your thinking the problem could be? I got the firing pin fixed but I have yet to shoot it. It took me a while to get it fixed and I have a big selection of 223 rifles I'd rather shoot than that. The only difference between this rifle and factory mini 14 is that the previous owner had an adjustable gas block installed. Could that play any part in this?
 
I no longer have my Mini 14, but as I recall, there is a tab that sticks out sideways on the tail end of the firing pin. It's purpose is to keep the rifle from firing out of battery. If the tab is broken off, that could be a clue as to what went wrong. If you don't know what you're looking at or what to look for, I strongly recommend you find a gunsmith who does. I'm glad you didn't lose any important body parts. Don't stretch your luck.
 
It looks to me like out of battery firing.
Click to expand...

I'm leaning towards a major gun problem rather than an ammunition related one.
Click to expand...

I'd say both of these guys are correct...

It's pretty clear (to me at least) that the cartridge was fired out of battery...

As for why, or how, I have no idea, unless it was a broken firing pin protruding as the bolt followed the cartridge into the chamber...

But then you'd think that the OP would know whether he pulled the trigger or it was a slam-fire?

If it was the firing pin that broke and caused the out of battery discharge, then you may have 'fixed' the issue by replacing the firing pin...
 
A properly working Mini, cannot fire Out of battery.

If that is what happened, the rifle needs to go back to Ruger.

Do not tell them it was a handload, they will refuse service and void the warranty forever.
 
Wogpotter could you elaborate on what your thinking the problem could be?
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That's very hard to do without having the rifle in my hands.
Here's what should happen step by step.
As the bolt comes forward it collects a round from the magazine & pushes it into the open chamber. At this point the bolt is rotated by the cam hump on the cocking handle. The firing pin's "dog leg" can't move forward because there is a slot in the rear of the bolt that is turned away from the dogleg.

In the final small movement forward the cam in the hump of the cocking handle rotates the "stub" on the bolt downwards, causing the bolt to rotate into its "horizontal (firing)" position.

As the bolt rotates the 2 locking lugs are forced into matching recesses in the receiver "locking" the bolt in place to keep it from flying open on firing.

At the same time the slot cut into the rear of the bolt lines up with the "tail" of the firing pin freeing it up to move.

Now & only now when everything is lined up & bolted shut can the hammer strike the rear of the firing pin & drive it forward to strike & ignite the primer. This is "In Battery" & is the normal, safe firing sequence.

"Out Of Battery Discharge" (OOBD) is a failure of these mechanisms to work together allowing the primer top be struck hard enough to ignite some time prior to the bolt's rotation into the locked position. The case is not held in place & blows backwards, forcing he bolt with it. The case ruptures & the high pressure gas vents down through the magazine as a safety blow out vent.

Usual suspects.
Broken firing pin at the "L" bend.
Bent firing pin jamming forward inside the bolt & firing the primer as it meets resistance from chambering.
Damaged/broken bolt lugs.
"Follow through" where the hammer does not "catch" on the hooks of the trigger & rides the bolt home belting the firing pin as it turns to lock.

You can check most of these functions by examining the firing sequence slowly with either a PROVEN SAFE unloaded gun & "Action Proving dummies" (dummy rounds with no primer or powder) or snap caps to safely simulate cycling with real ammo.
 
Notice how everyone wants to attribute the cause to a mechanical malfunction? I am going to offer a different cause: a sensitive primer. The Ruger M14 is based around the Garand mechanism. The bolt configuration, as seen in this exploded diagram on the Midway page, is just another variation of a Garand bolt.
https://www.midwayusa.com/General.mvc/Index/Schematics~ruger_mini_14

Garands have been slamfiring, due to primer sensitivity, since the day they were made. Garand mechanisms, such as the M1 Garand, M1a, M14, M1 carbine, and the Mini 14, all have out of battery slamfire reports. The firing is free floating, the mechanism does not have a firing pin block, and the firing pin is free to rebound off the primer. If a sensitive primer is impacted by a firing pin with sufficient energy to ignite the primer, a slamfire happens. In this mechanism, a slamfires can and do happen before lug engagement, and in which case, you had an out of battery slamfire.

I have no idea what primers were in your cases. The only proper primers for this mechanism are the least sensitive primers you can find, which would be the "mil spec" primers. There was a recent discussion on mil spec rifle primers in these threads.

Hardest Large rifle primers
http://thefiringline.com/forums/showthread.php?t=567572&highlight=military+primers

CCI 34 VS 200 primers.
http://thefiringline.com/forums/showthread.php?t=567902

This table is worth looking at:

CHOOSING THE RIGHT PRIMER - A PRIMER ON PRIMERS
http://www.sksboards.com/smf/?topic=56422.0
 
A slam fire means that a fully chambered round went off without pulling the trigger, yes?

If the mini was in working order, and there was a "Slam fire" the bolt would still have been completely closed, yes?

If the bolt was closed, then the offending round would have just went bang, sent the bullet down range, ejected the fired case, chambered the next round and surprise the hell out of the shooter.

I don't know how a "slam fire" in a properly locking bolt could exhibit what the OP has posted.
 
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Here's a picture of the firing pin

2470-1.jpg
 
I will remove excessive headspace because even though the primer did back out a little as seen on 2nd and 3rd picture.
Also I toss Double charge of powder because there is no cratering of the primer. There is indications of excess pressure but not extreme (on the case head).
I would question a squib or another barrel obstruction prior to this KaBoom.
 
Wouldn't a slam-fire leave a light firing pin mark as opposed to a full power dimple?
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Not necessarily. Slamfires are rare enough there are not a bunch of pictures of the primers. The two out of battery that I had with a Garand (and Federal Match primers), the primer indentations looked normal. I have seen two in battery slamfires in AR's, it is my recollection the primer indentations looked normal, but others have posted slamfire rounds from AR's and the primer indentation looked like a donut.

BartB saw many slamfires in Garand mechanisms, in battery and out of battery. He had been taught that only high primers and worn out receiver bridges cause slamfires, but the primer indentations looked normal. To reconcile what he was taught and what he was seeing BartB came up with a wacky theory to explain the phenomena he was seeing. I forget what his theory was, but it had to involve the hammer striking the firing pin.

The pictures are gone from this thread, the OP posted a picture of an out of battery primer next to a normal round and said

Other than the deeper indent, nothing else appears to be abnormal.

M1 garand cracked receiver

http://thefiringline.com/forums/showthread.php?t=491559


A slam fire means that a fully chambered round went off without pulling the trigger, yes?
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Yes.

If the mini was in working order, and there was a "Slam fire" the bolt would still have been completely closed, yes?
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No. This mechanism has more slamfire reports than all other mechanisms combined and more out of battery slamfire reports than all other mechanisms combined. In fact, out of battery slamfire reports in mechanisms other than Garand mechanisms are very rare. A few exist for the FN 49. The Garand mechanism was an early semi automatic and does not have safety features that were incorporated in later mechanisms. So while SKS's have lots of slamfire reports, try to find an out of battery slamfire report in an SKS. I have not. Murray's actually wedged a firing pin forward in a SKS, dropped the bolt, and the gun fired the magazine, but did not blow up. Do something like that in a Garand mechanism. It will produce a big badda boom.
 
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Notice how everyone wants to attribute the cause to a mechanical malfunction? I am going to offer a different cause: a sensitive primer.
Click to expand...

It fired out of battery. The tail on the firing pin is supposed to keep that from happening. If it didn't, well, sounds like a mechanical malfunction to me, sensitive primer or not.
 
What 223/5.56 powders can be double charged . None that I use can even come close . In fact half the time I can't even get one full charge . 4895 . 8208xbr , H335 , 4064 , RL-15 are my most used and none could give a double charge . Of those H335 could be over charged buy a few grains but still not close to double .
 
Theoretically
Note the use of the term.
A slam-fire could occur as the bolt is rotating down enough to have the bolt's dogleg over the bolt's channel but not be 100% locked shut.
Likely?
Gee, I don't know have the O.P. test it with dummy rounds. If the FP can't enter the firing channel with the bolt even slightly unlocked then no.
 
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