Quote:
Originally Posted by Grouse
(Post 77213)
Every Dan Wesson 1911 I own has been broken in on tula. first 1000 rounds at least. Since i have young kids and an active life, and a lovely wife. I choose not to reload. I have never had an issue with tula, period. 10's of thousands of rounds. Not saying their product is perfect, it stinks, it is dirty, yet it goes bang. It also fits in the 9mm match chambers of the guardian and pm9, along with the 45 chambers. Where as other cheaper ammo like winchester, umc, magtech, pri part, etc does not always seat fully.
While this may have been an over pressure. I did not see that. To me it looked like an out of battery detonation. That is the only way i see the case splitting, ripping at the base like that. Personally I believe there was some build up of gunk, likely from the ammo or poor cleaning, in the chamber. This kept the bullet from seating fully into the chamber. After a few rounds it built up to the point of keeping the back of the case out of battery. Then boom.
Another cause could have been poorly seated bullets. as he fired the first few rounds the remaining bullets moved further forward. elongating the OAL. Finally the cases was not supported and boom.
Both of these can cause this issue at standard pressures. I have seen over pressure failures and they are far more catastrophic. If the cartridge had been in battery, an over pressure would have blown the whole barrel along with the breach like it did. In my exp out of battery detonations only blow the case and the breach. Causing damage to the breach, action and stock.
I had an over pressure in battery detonation on a 22lr pistol. it bulged the barrel to the point it would not come off the slide. Sig replaced it no issues. the rear of the case did not split. That same gun had numerous out of battery detonations, because i only cleaned it when i wanted to torture myself. Every out of battery detonation the case split exactly in this way. I have also seen it on a few center fire rifles of pistol caliber. (older lever actions) chambered in 38/357. where the home reloads were not crimped enough. After a few rounds boom.
My 2 cents in a world of twenty dollar bills.
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I'll try to take these in some kind of order but, some of the info will overlap.
1.) First of all, this was a fairly new rifle. It was built by a reputable Smith. Had a fairly new indexed and headspaced barrel
.
2.) The Bolt. Garands have what's called a Safety-Bridge system in them. This system holds the floating firing-pin's hook or, Hammer-face back until the Bolt goes into battery. Then it is cammed onto place at some speed(This is why a chambered round in a Garand will have a slight dimple in the primer-face). There is nothing else to cause the primer to function in the receiver. If one looks at the prints or, is mechanically inclined enough to understand the way it's built and designed, you will see that in the event of an over-pressure blowout, the gas is directed down into the bottom of the receiver. Once it gets down there the Stock, being the softest material involved, splits from said pressure.The only time you'll get a barrel-bulge or split is if a foriegn object is in the barrel.
3.) Out of battery detonation. Didn't happen here. Gentleman involved stated it happened on a trigger-pull. This means the bolt was fully into battery. Trigger and hammer won't fire if the gun is assembled and out of battery. Also, the reason the guy had to bang on the Op-Rod Handle to break the bolt loose. The tear right at the base was in part, due to the M1's Extractor. While I have no doubts as to what happened, an Over-pressure load, pure and simple, If you look at the pic below this para, you'll see the M1's massive Extractor is in the exact position the casehead tear is. Also, you'll see two openings on the breechface, one at three O' clock and another at around nine O'Clock. These are pathways for over-pressure gases to travel down into the receiver. You'll also notice the sealing ring is not continuous, more pathways for gas.
http://i264.photobucket.com/albums/i...3/IMG_0081.jpg
Ejector at six O'Clock and Extractor from 7 to 11 O'Clock.
Here's what, in all probability happened. You have a newish barrel with probably a tight chamber and you have a steelcased round with an overload charge of powder. Now, steel cases do not act like a brass case does. Steel Cases do not expand or contract like brass cases. In this case the round, an obvious over-charge, ignites, the steel tries to expand but can't due to the chamber. There are only two ways for the gas to go, out behind the bullet, which will still present a high overload condition in the case or, out the weakest part of the case which is right above the casehead in the rebated area and this is what happened along with the case-body pressure-affixing itself to the inside of the chamber. When he tried to open the bolt by hitting on the Op-Rod handle the Extractor, in place, tore the already damaged casehead.
As for the rounds going over-length while firing, can't happen in a Garand. The barrels, 30-06 or .308, have less than a 1/4" of leade. The bullet would simply catch the rifling and be pushed back into the case until the round chambered. Further, over 90% of Garand ammunition, military, commercial and reloaded doesn't employ a crimp. The bullets are held by Neck-Tension. Here's a pic of an En-Bloc of my 168SMK Match-loads, note there is no crimp.
http://i264.photobucket.com/albums/i...3/IMG_0269.jpg
So, we had a case that couldn't expand or contract properly due to material used and an over-charge of powder plus a tight commercial chamber. Ka-Boom!
