Most Saturdays 3 or 4 of us hold an informal 36 rd. mini match at 100 yds. During my sons RF/S string his rifle doubled on the 8th or 9th rd. Normally a double is just annoying and I've found the shooters fault most often, however this one knocked him over as the back of the receiver broke out and hit him just below the eye. He'll have a bruise, but no permanant damage. The rifle is an HRA 5.5 million with an Orion installed 308 barrel and SS op rod spring. Rds. used 4064 well below max and all rounds were put thru a Wilson guage. Any ideas on what happened here, we sure don't want to repeat it soon.

Rifle might have been a reweld-check it out to verify.

I remember there being a picture of a receiver heel split at Camp Perry in the GCA journal a couple of years ago. I guess there are a few possibilities. The gun might have been fired so many times that it simply wore out (unlikely). This owner or a previous owner may have used a lot of abusively stout ammo in the past--some of these match shooters do things to garands that will break your heart. Or, some minor flaw in the metal finally undermined it enough to cause failure.
My bet is its one of the last two.

My recollection (someone jump in if they know of statistics one way or another) is that when it comes to M1 Garands, the correlation between "308" and "receiver failure" is a lot higher than 30-06.

And yes, what dubious approaches some match shooters were willing to do to a Garand in the quest for a few more points could make Jesus weep.

I have a Garand that has been declared unsafe due to receiver wear. It was a Blue Sky Korean import. It gauged fine when I bought it, but failed after about 2k rounds of US surplus ammo. They DO wear out the receiver.

Yes, there is a theory (probably a good one) that the .308 Garands are more prone to slam fires because the bolt gets a little longer run when chambering a .308 round.

But some say it's offset by another factor.
(I tried to think of a good way to describe this, and this is the best I could come up with.) The .308 case is slightly wider at the point a Garand clip's front edge falls on the cases. Said another way, the clip has to spread a little more to hold eight .308s than it does for 30-06s. This causes the clip to grip .308 cases harder. Try stripping the rounds from a clip of .30-06s and a clip of .308s and you will feel a little difference.
Some say this slows the bolt down enough to help. My .308 Garands are more prone to need a "handle bump" to chamber the first round than the 30-06 rifles. But they don't always need it.
I think that with the differences in the tension among the zillions of clips out there, there are bound to be some that are looser than others and allow the bolt to close at a faster speed, negating this idea. And obviously, if the clip's tension on the cases determine whether a slam-fre happens or not, things are getting pushed too close.

I would look at the usual slam-fire culprits.
Find out the primer used.
Check out the reloading practices.
I would especially check into what brass was loaded and how it was loaded. Find out if he checked it in his chamber or a gauge before shooting it. With the ammo/component shortages, people are getting less picky and there is less to be picky about. The last order of .308 military brass I got was evidently fired in MGs with sloppy chambers. After sizing some in the .308 die I usuallly use, it wouldn't fully chamber in a couple of rifles. I dug out one of my other .308 dies (not a small base die) with tolerances on the smaller side. After resizing with it, they chamber just fine. There wasn't much difference in the sized dimensions, but it was enough. Had I just used the first die and ran the ammo through a Garand, I could have set up a slam-fire if other conditions were right.

There's also the disparity between bolt-gun reloading practices, and self-loading.

With bolt guns, you can get away with minimal sizing and getting the best fit to the chamber. With self-loaders, yo uhave to "bump" the shoulder back to minimum, or you're asking for trouble. A lot of reloaders, when they start to notice the problem, assume they need a small-base sizer, when the problem is actually at the other end.

The "problem" with doing it right is you decrease brass life. So what? It doesn't last forever anyway.

To clarify some things, the rounds used were loaded with a 125 grain BTHP bullet. Again well below published max data and Kuhnhausen warns against heavy bullets, but could lighter than ball be a problems also? The receiver by the way was from CMP.

A double with a busted receiver does not sound like truly a kB!.

To give my semi-edjoomated opinion, I'd have to examine the trigger group for signs of jar-off or something caused by the receiver breaking on the first rearward cycle of the bolt, and look at the bolt and receiver lugs for signs of when the second round fired.

I've studied true out of battery events which usually include rounded receiver locking lug corners, and which *could* result in higher-velocity op rod/bolt travel, which *could* in turn lead to a cracked or broken receiver. Have heard no accounts of receiver heels getting broken off from these, but there is always a "first".

I've also seen accounts of receiver cracks, usually from extended use of too-slow powders or out of spec reloads. IIRC, there was one report specifically of the heel getting cracked.

To smack the shooter's face, the receiver would either have to crack on both sides behind the rear receiver "lug" at the back of the internal clip-feeding mechanism, or break away from that point with the failure at the more typically weaker points further forward.

As described, this double was most likely NOT caused by what is sometimes called "bump firing", common enough with some lighter trigger jobs. However, leaving not enough overlap between safety sear engagement and the primary sear picking up the hammer hooks, there is still the chance that a mechanical failure in the trigger group could have caused a doubling which just happened to occur on the very same shot where a compromised receiver let go.

Are we talking about a situation where the receiver heel broke all the way off and just flew? Or were there still bits left attached that resulted in rearward displacement but otherwise still being trapped by the stock?

The weight of the bullet is less important than the port pressure. Though not fully comparable, I have seen pressure data showing that with WW748 in .308 and in the M14-type, the lighter bullets gave higher port pressure than the heavier ones. Can't say if that would still hold true further down the bore of a 24-inch barrel, though. I can't even remember the port pressure specs for the Garand...

Grump, The entire back end of the receiver heel gave way. I don't have the piece to inspect at this time, but memory had it about 3/8 inches in width. We're still looking for an unaccounted for rd. somewhere lost in a pile of wood or just hiding, thinking it may tell us something, but I'm sure it was loaded no differently than all the others.

Photos? They would give the Site Gurus more information to work with.

So, it was only that quite thick section that came back? No "sidewall" portions, for lack of a better term?

Wasn't the Garand slightly re-designed just before final adoption to ensure that the op rod travel was stopped at the front end of the receiver (in front of the receiver rail tracking portion), and to make sure that the bolt was no longer being forced back by the op rod for the last 1/4-inch or so of its travel inside the receiver? I remember something about letting the bolt bounce around back there before being picked up by the forward motion of the op rod, which slowed the operating cycle enough to give the next round fully enough time to rise into the feed position under all conditions.

Bottom line--the bolt, IIRC, is the only thing hitting inside the receiver heel, and it's released from being pushed by the op rod before it hits.

My son talked to Anthony@ Orion. Although I don't have all the details, it's Anthony's opinion that the lighter weight bullets were the culprit. Not sure if it's a pressure curve thing or not. More info as I get it Thanks for all your replies.

From earlier:


Exactly. It would be a pressure curve thing, just like the excess port pressure effect with regular-weight bullets and too-slow powders. A lot can change out there at the gas port, with the number of new powders introduced since the Garand was adopted in 1937.

I think the guy who has this forum had a similar incident. I don't know if it was a 308 or a 30-06. kwg