I'm interested to get Ren and Teichi's takes on this incident as they probably have a bunch of experience with M1's from the CMP (GZ doesn't have any experience with M1 & variants).

I am the person this happened to. The 7th round jammed, which is nothing unusual for this gun. It happens all the time. That is why I didn't really hesitate to shoot the final round. We were using newer ammo, so we don't think that's the problem. My brother has been looking at his M1, and we noticed it will still fire with the chamber not fully closed. The chamber can be open up to 1/2" and the weapon will still fire. We think that's what happend.
arizonagirl24 2 days ago

I was very lucky with the outcome. I have lots of splinters and bruising, but nothing broken. My left hand took the brunt of the blow to my wrist and palm of my hand. Still pretty painful, but I will be fine. Thanks for the concern.
arizonagirl24 2 days ago 13

The 7th round was a live round. The M1 jammed like it often does. Instead of forcing that round into the chamber, I took it out and slammed the bolt forward. We are thinking the chamber did not close all the way. My brother's M1 will still fire that way.
arizonagirl24 21 hours ago

Slam fire, huh? 

Wow crazy video

dam, that's nuts.   thanks for sharing. 

Slam fire, huh? 

I'm at work so I've been looking at that clip without sound, but I'd say it doesn't look like a slamfire.  Also haven't read all the comments either, but it almost looks like a squib blocking the chamber/barrel.  That's why I wanted to get Ren/Teichi's input because those guys would probably have some really good insight for the rest of us who aren't familiar with that platform. 

In any case luckily that gal is OK.

I don't think it sounds like a squib, although I've never heard one.

It may have been a squib. I'd have to examinethe extracted shells andthe rest of the wreakage to be sure.

If the rifle can fire 1/2" out of battery then that could have done it. The rifle should not be able to fire out of battery, and the problem should have been addressed before any rounds were fired.  If the gun is not working, jamming, etc it should be fixed.

Didn't look like a squib load.

From the looks of it, she didn't pull the bolt back far enough to really slam shut.  It may have closed, but did not fully lock up.

They knew it was malfunctioning, they should have had it checked out/repaired before shooting it.

EDIT:   Not commonly known.  M-1 Garand Clips have to be loaded with first round being stripped from one side first.

Forget which side is the High side.  This may be the reason for the 7th round malfunction.

Another reason to use a single stage press when reloading Rifle rounds.  Can easily check for "high" primers.

Also use small base sizing die for use in auto loading (military) rifles. 

Case NOT full length resized MAY stick in minimum size chamber and not allow bolt to fully close and lock before firing pin hits = KaBoom.

Wait til you have the M-1 double/triple on you because of bad parts.

Watch WWII Pacific theater combat footage of Marines double/triple tapping the M-1 in combat. 

The Garand could not be made to blow up, even with the highest proof loads that could be made up, namely 120,000 psi (CUP), according to the Ordnance Department tests, although cracked left lugs started to appear. The test rifle continued to function normally with standard pressure rounds after that.  However, this was with a fully closed bolt and no barrel obstructions. By contrast, a 100,000 pound shot could be depended upon to burst a Springfield rifle receiver.

Occasionally, firing with the grenade launcher blanks resulted in cracked rear walls of this rifle.

The previous round did not sound like a squib.

The rifle did not discharge when the bolt was "closed," as one would expect with a high primer or stuck firing pin.

The tentative conclusion would be that the bolt was not fully closed and the brass let go.

This reinforces the "Fifth Rule," that when anything out of the ordinary occurs when shooting, one must stop firing and investigate until the problem is cured... as noted above by others.

I am pleased that no serious injury occured.

I also note that many times on the high-power range (in my competition days circa 1970), folks would give the operating rod handle an extra rap after releasing it, to ensure that the bolt had really been closed.  I always followed this practice, as a matter of imitating the "big boys" at the range.

(I follow this same practice with the M1 Carbine, as these have essentially the same closure mechanism, and with the SKS, to insure that the bolt carrier has actually ridden over the "hump" of the bolt.)

Terry, 230RN

REF:

Hatcher's Notebook, Chapter 8, "The strength of military rifles," p. 198 ff, specifically pp 205-206.

It looks to me like she was "riding" the bolt handle forward.  Don't know much (anything) about M1's, but that's a recipe for firing out of battery in a semi-auto pistol.

A friend of mine has a 91-30 Mosin Nagant , and he recently discovered that he had screwed up big time (using data from on powder for another) and overloaded 20 rounds by 5 grains of powder.  He figured this out only after shooting all of them ('cause the primers were so flat); other than being really loud, the rifle didn't notice.

Yeah, riding the bolt handle on an M1 is a really big no-no.

^ Five grains over isn't too, too bad if he was using light bullets of .308 diameter and was starting at the minimum loads usually listed... around 45-ish grains of whatever --especially if it was a slow powder.

Not good, mind you, but not too, too bad.

The  flattened primers might be a somewhat exaggerated indication if he was using American primers, which are usually pretty soft compared to some foreign ones.

Still, I'm sure it was a damned good lesson for him.

I'd prefer the factories do the proof shots for me, though

And you know what they say about Mosin-Nagants... decades of Communist oppression have made them impervious to damage from any cause.

In reloading, double-check your double-check, and eliminate the possibility of distractions.

Terry, 230RN