M1 Garand Slamfires

On my last range trip I had an issue with my Springfield M1 that I am hoping some of the members here might be able to help me solve. After firing about 750 rounds over the course of the year that I've been shooting it, the rifle slamfired twice. For both instances, the rifle was feeding from a full 8-round clip and fired the 2nd and 3rd rounds with one trigger pull. The ammunition was Greek HXP dated 1976 bought from the CMP (200rds loose). I am certain they occurred when the bolt was locked, the gun was not damaged in any way and all brass is perfectly intact. Before the slamfires I went through a clip of Danish ammo with no issues. Between them I grabbed my only clip of 1970 dated HXP ammo and also had no issues. I found the brass from the slamfires (the only '76 stamped brass) but couldn't distinguish which ones were which. All have similar primer indentations.

After the second slamfire I decided to quit for the day. I didn't have any other ammo with me and I wasn't entirely sure the issue wasn't mechanical, since the rifle was due for a thorough cleaning. I was able to do this yesterday. The rifle didn't seem unusually dirty and the trigger pack appears to function (hammer release, disconnector, and reset). I did notice the tip of the firing pin was damaged (please see attached pictures). Looking at some old brass, I can see the firing pin indentation is not very clean, so I am guessing it has been at least partially damaged for a little while. Some of the damage looks like dents and some look like chips, so I may have missed it the last time it was taken apart and it got worse with firing.

So, the questions are:
1. Is it possible the slamfires were the fault of the HXP ammunition? I've shot about 196 rounds of '70 dated ammo with perfect reliability and the only instance I have been able to find online of an HXP slamfire was from someone who manually slammed the bolt on a chambered cartridge. Maybe I got unlucky and this can has a bad lot of '76 ammo mixed in?
2. Is it possible the damaged firing pin is to blame? It doesn't look great, but it fully retracts behind the bolt face when assembled, so I have a hard time believing it could be the culprit.
3. Is there anything else that could have caused slamfires?
4. Should I replace the firing pin even if it did not cause the slamfires?

Thank you in advance for the advice!

It could be a couple of primers not seated completely into the cartridge case, aka high primer. For the cost, I'd replace the firing pin, but I have seen worse.

I would not be worried about the tip, the ridge where it tapers would be my concern, maybe sticking there , replace the pin.

Firing pin doesn't look to good, look at your bolt face and see if you can see where the opposite is happening in the firing pin port.

The question about the pin probably should not have been should I replace it, but rather is the damage normal wear? I saw the CMP has replacement pins for $21, so that's not a big deal.

Looking down the rear of the bolt, the firing pin channel looks good and circular. From the bolt face side it is not quite circular, possibly a chip that corresponds to one of the dents in the pin. Still not sure what would cause this though. I do not dry fire the rifle, I always use a snap cap.

When this happened, were you bench resting it?

I have had that happen when I was bench resting my M1 and didn't have the gun shouldered tightly.

A Garand firing pin "floats", if the tip of the pin is sticking in the firing pin port it can detonate the primer when the bolt returns to battery. Make sure the port is clean from grease and debris. Make sure you firmly manipulate the trigger and hold the rifle firmly. Double check for unloaded and then let the bolt close home, pull the trigger to the rear and hold it tight. Then with your left hand retract the bolt about 3/4 of the way back, let it go into battery, release the trigger. If you then pull the trigger and then you cant hear the hammer drop you may have have other issues to check into.

I was bench resting it, but I am certain I didn't bump fire. When bench resting I hold the stock in my shoulder with my support hand, its never gotten away from me like that.

@Doco - I did exactly that before taking it apart. The hammer catches the disconnector and the trigger resets like you'd expect.

Can you post pictures of the bolt face, maybe the firing pin tip has started to crater it out and the problem is mostly evident with specific ammo and primer sensitivity. Someone with more experience will jump in I'm sure. The pin will move radially but only a little bit, the damage is more on one side than the other but is visible on the other side. What's the other end look like, is it all mashed up or bent? Opposite the lightening cut and where the radial wear is, the wear pattern has been burred where the pin has a convex shape. Reach into the bolt with a fine piece of stiff wire and try to feel for burrs on the convex seat.

That firing pin needs replaced before firing rifle again! What does the other end look like on the tang?(inside curved section)

What you describe is not a slam fire but your rifle doubled. Make sure there is no grease on hammer hooks and trigger sear, the inside of bolt should be clean ,free of grease , dirt etc.

Orlando said:

That firing pin needs replaced before firing rifle again! What does the other end look like on the tang?(inside curved section)

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Why do you say that? I can show you a few that are worse than that and the rifle functions fine.

j_h_smith said:

Why do you say that? I can show you a few that are worse than that and the rifle functions fine.

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That pin is badly damaged, they should be smooth with no chips, can cause pierced primers. Its a badly worn part.
I suspect the tang is also worn/ damaged which can cause function issues

First, slam fires in a Garand are rare. I'd first get the head space checked out and then take a close look at the wear on the bolt as excessive bolt wear can lead to a slam fire. Do not fire that rifle until you resolve this problem! You are dealing with way too much pressure.

My Garand advisor and I own over 200 Garands, shoot them regularly, like today, and we've talked about the subject and as far as we are concerned, it's not an issue, even when switching out bolts. I've owned Garands since 2002 and this is the first time I've read about one slam firing...let alone twice in the same outing.

I'd try a new bolt and get the spacing checked real fast. I have spare bolts if you want to contact me offline.

I will be at the AGC lower range house around noon today, and my friend whom I am meeting could inspect your rifle. He has all the gauges for checking out a Garand.

Lew--Ranger63
Infantry, Airborne, Ranger, Dual Rated Army Aviator

I'd be curious to see the primers on the rounds that slam fired.

Replace the firing pin! That is the most likely cause of your issue. Have the bolt checked as well since you state that the firing pin hole is out of round. If you can, stop by the AGC today and take advantage of good guy 176's offer and have it checked out with the proper gauges. I plan to be there also.

The Receiver:
1
The first part of the M1 Garand we are going to inspect is the receiver. The receiver is the foundation of the rifle and on the M1 Garand there are several areas we want to look closely at. the first area we are going to inspect is called the bridge. As the name implies it is the piece of metal that bridges the two sides of the receiver about midway down. The bolt rides through the hole in the bridge. If you look closely you'll notice a notch and a ramp cut out in the bridge. This is a critical safety feature on the M1 Garand. This area is designed to prevent the firing pin from striking the cartridge until the bolt has cammed shut and the firing pin aligns with the notch in the receiver. As the bolt begins to close, the ramp on the bridge pulls the firing pin away from the primer. When fully closed (in battery) the firing pin aligns with the notch and allows the bolt to strike the firing pin tang. Verify that the bridge is not cracked and the ramp is in good condition.
Inspect the heel of the receiver for any signs of cracks. The heel of the receiver is the around the serial number of the rifle.

A simple way to test a suspected crack is to saturate the area with kerosene or mineral spirits, then quickly wipe dry the surface. If a crack exists then the solvent will weep out of the crack leaving a glossy line at the crack location. Spray dies to detect cracks can also be purchased at your local auto supply store.
2*
Next insert the bolt in the receiver without the op-rod attached. Slowly rotate the bolt into battery and verify that the firing pin is retracted as the bolt closes.

1
The first part that you'll want to inspect is the firing pin. On the M1 Garand the firing pin is free floating. It should move freely inside the bolt. It is normal for the firing pin to slightly dent the primer when a round is chambered. The firing pin does not have enough kinetic energy to fire the primer and this process does not pose a safety hazard. For this to be true the firing pin must move freely and not be stuck in the bolt. Old grease or cosmoline can jam a firing pin causing a safety hazard.* Always disassemble and clean the bolt before you fire your M1 for the first time.* A few drops of oil spread over the surface is all the lubrication required for the firing pin.
Start by inspecting the firing pin tip. The tip of the firing pin that strikes the primer should be free from chips or burrs and should be straight.* It's normal to have the parkerzing worn in and around the firing pin. This is not indicative of a problem and is considered normal wear. The surface should be smooth and not pitted from rust.

2
Next inspect the firing pin tang. This is the part of the firing pin that is struck by the hammer. This part of the firing pin is the most common place for a break to occur. Check the tang for chips, cracks or abnormal wear. The tang works with the receiver bridge to retract the firing pin as the bolt goes into battery. If the tang is worn or broken this critical safety feature may not function properly. The firing pin should be replaced if it fails inspection.

[This worn firing pin is nearing the end of its service life]
3
We next want to measure how far the firing pin protrudes from the bolt face. Push against the firing pin tang until the firing pin extends fully above the bolt face. Measure the height from the bolt face to the tip of the firing pin. The firing pin should extend between 0.044" and 0.059" above the bolt face.* When retracted the firing pin should be completely below the face of the bolt as shown in the image below on the right. With the firing pin retracted inspect the hole in the face of the bolt for chips or damage. The firing pin must move freely. Maybe they'll have a receiver bridge gauge to prove your receiver has remained in spec.

Orlando said:

That firing pin needs replaced before firing rifle again! What does the other end look like on the tang?(inside curved section)

What you describe is not a slam fire but your rifle doubled. Make sure there is no grease on hammer hooks and trigger sear, the inside of bolt should be clean, free of grease , dirt etc.

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^^^ This.

I'm surprised that nobody else mentioned checking the sear. With a firing pin that looks like yours, there's also a fair chance that the sear is also damaged or worn.

I agree it sounds like doubling, not a slam fire.

Did not see the OP at the range today. I suggest taking the rifle to Charlie Maloney and have him inspect it. Charlie is a top notch Garand armorer.