M1 Garand in .308... ammo questions

[enichols]

Hello All,
My favorite rifle is my M1 Garand in .308win. It's a 3.7mil SA receiver with a brand new Fulton Armory .308 barrel. It is a wonderful rifle.
When I had the rifle rebarreled, my gunsmith told me that it would be OK to fire 7.62x51 NATO surplus ammunition in the rifle. I figured that this would be fine, because I was under the impression that the pressure generated by an
M80 7.62x51-equivalent load is about the same as .30 M2.
That being said, I have fired 500 rounds of SA 7.62x51 surplus and about 40 rounds of IMI 7.62x51 through it with nary a problem. No bent operating rod, no cracked receiver, no nothing.
Now here's the thing... I've been reading this message board and several others and the discussion about people destroying their M1 rifles with ammo other than M2 ball scares me. I am literally afraid to fire anything through my Garand after all of the reading I've been doing, which seems a little counter intuitive considering that so far everything has worked just fine, without damaging the rifle. I also considered that since the Navy rebarreled many
M1s into a 7.62x51, firing that round would be OK.

Advice? Suggestions? There is literally so much information (much of it contradictory) that I am a bit overwhelmed, and like I said, now I'm really worried about firing my rifle for fear of damaging it.
Any input would be helpful.
Thanks,
Nic

 

[Jeremy2171]

Nato ball and M118 Match equivalents are ok. Stay away from the M118LR as it beats up the M14 pretty good.

 

[Slamfire]

The basic problem with 308 Garands is that free floating firing pin. The Garand has a long firing pin and it is not really restrained by much of anything. As the bolt goes forward, that firing pin is just tapping away on the firing pin. Since the bolt goes all the way back on a Garand, with the 308, it has half an inch of acceleration before it picks anything up. When the bolt stops to cam over, that’s a dangerous spot. In theory the receiver bridge prevents the firing pin from going forward, in practice it does not. Ammunition with sensitive primers have been known to slamfire at that point. If the lugs are engaged, then nothing bad happens. If the lugs are not engaged, the cartridge will rupture, stocks will split, the back end of the receiver will come off.

How do you know if your mil surplus ammunition has sensitive primers?, by the slamfires you have.

I suspect the greatest problem I have had with mil surplus is the stuff is not loaded for the Garand type action. Most of that stuff is quite hot. I have had torn extractor rims, which is an indication of the action opening too soon. You should notice a just perceptible “clip-clop” as the bolt cycles if you are using appropriate ammunition. If it is all just a big bang, your ammunition may be on the hot side.

If you decide to every reload, full length resize your cases, size to cartridge headspace gage minimum, use a small base die, and prime with CCI #34 mil spec primers.

 

[Jeremy2171]

SlamFire1 The basic problem with 308 Garands is that free floating firing pin. The Garand has a long firing pin and it is not really restrained by much of anything. As the bolt goes forward, that firing pin is just tapping away on the firing pin. Since the bolt goes all the way back on a Garand, with the 308, it has half an inch of acceleration before it picks anything up. When the bolt stops to cam over, that’s a dangerous spot. In theory the receiver bridge prevents the firing pin from going forward, in practice it does not. Ammunition with sensitive primers have been known to slamfire at that point. If the lugs are engaged, then nothing bad happens. If the lugs are not engaged, the cartridge will rupture, stocks will split, the back end of the receiver will come off.

If the lugs aren't engaged it doesn't matter what caliber it is...you just had an out of battery firing...not good. If the lugs weren't engaged then the receiver bridge is out of spec or the F. pin may be stuck or broken forward....again this has nothing to do with what caliber it is. The receiver is uservicable if the bridge is worn.

How do you know if your mil surplus ammunition has sensitive primers?, by the slamfires you have.

I suspect the greatest problem I have had with mil surplus is the stuff is not loaded for the Garand type action. Most of that stuff is quite hot. I have had torn extractor rims, which is an indication of the action opening too soon. You should notice a just perceptible “clip-clop” as the bolt cycles if you are using appropriate ammunition. If it is all just a big bang, your ammunition may be on the hot side.

NATO milsurp is loaded the same. The Navy rebarrelled and and ordered/issued NATO 7.62 in Garand clips. So NATO 7.62 is "perfect" for the Garand.

If you decide to every reload, full length resize your cases, size to cartridge headspace gage minimum, use a small base die, and prime with CCI #34 mil spec primers.

Small base dies and CCI primers are over rated. WLR's have worked for me for 12+ years with not one slamfire.

 

[Slamfire]

Small base dies and CCI primers are over rated. WLR's have worked for me for 12+ years with not one slamfire

WLR nickle plated primers were the best. But Winchester changed their primers, removed the nickle, made their primers more sensitive, and made the cup thinner. (I just went through the National Matches using the old nickle plated WSR. Not a single one pierced. I cannot go through a magazine of the new brass WSR without getting a pierced primer.) Someone on the Firing Line Forum reported a Garand Slamfire with the new Winchester primers. I don't recommend them for Garands anymore.

When you have your first out of battery slamfire, you might reconsider the use of CCI primers and small base dies.

 

[Sunray]

"...with ammo other than M2 ball..." M2 ball is .30-06 with a 152 grain bullet at 2800fps only. The rifle was designed to use .30 M1 ammo with its 174.5 grain bullet at 2640fps. There was no such thing as .30 M2 until 1940.
You can relax though. You don't have a .30-06.
.308/7.62NATO is ballistically identical to .30-06. If you're not reloading, any NATO spec ammo will do nicely. Just don't expect astounding accuracy with any milsurp. It's not made for that.
If you are reloading, use 165 grain hunting bullets and/or 168 or 175 grain match bullets with IMR4064 or IMR4895 and regular large rifle primers. 168's for distances up to 600 yards, 175 grain Matchkings past 600. IMR4064 gives more consistent accuracy than 4895 does.
CCI "milspec" primers are a marketing gimmick. Lots of .30-06 and .308/7.62 was loaded and used with no fuss long before CCI came up with them.
You don't need a 'small base' sizer die either. A regular full length sizer die will be fine. Full length sizing every time is required though.
Slam fires are caused by improperly seated primers. The hardness of said primers doesn't matter.

 

[Slamfire]

CCI "milspec" primers are a marketing gimmick. Lots of .30-06 and .308/7.62 was loaded and used with no fuss long before CCI came up with them.
You don't need a 'small base' sizer die either. A regular full length sizer die will be fine. Full length sizing every time is required though.
Slam fires are caused by improperly seated primers. The hardness of said primers doesn't matter

CCI milspec primers are a different product line for CCI. It is their military primer product line. Call them up and ask them.

You may not be aware that primers are all made to specifications, and specifications can change. What was procured as a military primer twenty or thirty years ago was not necessarily what was on the civilian market then, or now. The trouble for us is that primer manufacturers are not going to release their primer lot acceptance data. They are only going to tell you that their primers are made to SAAMI specs. But the fact of the matter is, some primers are more sensitive than others.

I do believe that a high primer can cause a slamfire, but the primary mechanism for slamfires in Garands and M1a’s is primer sensitivity. If a firing pin has enough energy to ignite the primer, and it hits the primer, the primer will ignite. Both the Garand and M1a have free floating firing pins. Almost all other semiauto matic mechanisms have spring loaded firing pins to reduce the inertial impact energy.

A small base die reduces the chance of delay of bolt closure. If the round is a little fat, or a little long, the locking sequence is delayed as the bolt cams the cartridge into the chamber. That delay has resulted in out of battery slamfires. It is far better to have the rifle slamfire with even the tiniest amount of lug engagement.

It is all a matter of risk reduction. Kind of like wearing safety belts. Never had an accident, hope I never do. But one EMT I was squadded with told me that in 17 years of body bagging, he only saw two fatal accidents where the people wore safety belts. One was a truck wrapped around a tree trunk, however the truck was ten feet off the ground!

 

[Ian]

Since the bolt goes all the way back on a Garand, with the 308, it has half an inch of acceleration before it picks anything up.

For the record, this isn't quite accurate. The empty space in a .308 Garand mag is at the front, not the back. The bolt picks up a cartridge at the exact same sopt it would in an '06, and since the clip holds .308 and .30-06 round identically, there's no appreciable difference in the bolt-slowing friction between the two cartridges. The only factor would the minutely greater inertia of an -06 round because of it's very slightly greater mass (more brass).

Foe what it's worth, Nic, I think a lot of folks exaggerate the ammo sensitivity of the Garand. Like Sunray said, the original combat loading was a heavier, slower bullet than the later M2 load.

I've shot thousands of rounds of various types of surplus (Port, Aussie, South African, Argentine, German, even Indian before I knew better) through my .308 M1 and had no trouble. If you want to be totally safe, just get an adjustable gas plug, and set it just open enough for the rifle to cycle reliably.

 

[Slamfire]

For the record, this isn't quite accurate. The empty space in a .308 Garand mag is at the front, not the back. The bolt picks up a cartridge at the exact same sopt it would in an '06, and since the clip holds .308 and .30-06 round identically, there's no appreciable difference in the bolt-slowing friction between the two cartridges.

I believe you are correct. However I heard of more slamfire incidents with 308 Garands than 30-06 Garands. I just made the assumption it was due to a faster moving bolt, and forgot about the pickup point.

 

[Sunray]

"...primers are all made to specifications..." Of course they're made to specs. Everything the military, anywhere, uses is made to a spec. CCI #34's, their alledged 'milspec' primer, however, are marketing things. So are small base dies. Neither are required for safe loading for the M1.

 

[hps1]

Sorry, double post.

 

[hps1]

I do believe that a high primer can cause a slamfire

A small base die reduces the chance of delay of bolt closure. If the round is a little fat, or a little long, the locking sequence is delayed as the bolt cams the cartridge into the chamber. That delay has resulted in out of battery slamfires. It is far better to have the rifle slamfire with even the tiniest amount of lug engagement.

I have put a lot of rounds downrange through M1 Garands & M1A's but not too much experience with the AR's and none w/AK's, so following refers to the M1/M14 types.

Other than a dirty chamber, a broken firing pin or a pin that is no longer free floating for whatever reason, IMHO, ammo is probably the number one cause of slam fires. Anything that can cause the round to "stop short" of full chambering can result in the firing pin hitting the primer with sufficient force to set it off, due to the free floating firing pin. If this occurs before the bolt is in battery, it can be disastrous!

Soft primers can result in slam fire and the CCI #34 military primer has a hard cup to duplicate GI ammo, most of which is loaded with a hard primer. Handloaders must be aware of two other factors in order to avoid slam fires.

First, make it a practice to run your thumb over the primer as each round is removed from the press to be sure that the primer is fully seated.

Secondly, each cartridge must be sized sufficiently to fit chamber giving proper headspace clearance. I would not load for any "gas gun" without using a cartridge case gauge. Best practice is to run each case through the case gauge at the time the loaded round comes off the press. At the very least, spot check every few rounds in a given lot of reloads (for this to be acceptable, one must keep all brass in lots that have been fired the same number of times).

To illustrate the importance of the above statement, had a friend who is a very experienced highpower competitor and reloader who wrecked his match grade .308 M1 Garand using the same handloads he has used for years when the rifle slam fired only partially in battery. Bent his op-rod, blew extractor/ejector out of bolt and rounded the receiver locking lug recess about 1/8" showing the bolt lug had barely entered the recess and was not in battery at the time the slamfire occured. He received a cut on the forehead and had a little problem with his trigger control for a while afterwards. Fortunately, the rifle, and his shooting ability have since been repaired.

Upon examination of the remaining lot of ammo, we found that the rounds did not have sufficient headspace (clearance) in his snug, match chamber. He had loaded this batch of ammo using the same die setting as always and other lots measured OK. The problem stemmed from the fact that this particular lot of brass had been fired quite a few times and had work hardened and his dies had been set to give proper headspace with once fired brass. The harder brass springs back more than softer brass after sizing.

Anything that causes the bolt face to contact the primer before rifle is in battery can cause a slam fire. Cartridge case insufficiently sized, high primer, dirty chamber, etc.

I have never used a small base die; IMHO they tend to overwork the brass and can cause case head separations. I prefer to use a cartridge headspace gauge and measure once fired brass from my rifle, then set my full lenght sizing die to size the case .0015-.002" under the once fired case headspace reading obtained for my rifle.

For the record, this isn't quite accurate. The empty space in a .308 Garand mag is at the front, not the back. The bolt picks up a cartridge at the exact same sopt it would in an '06, and since the clip holds .308 and .30-06 round identically, there's no appreciable difference in the bolt-slowing friction between the two cartridges.

This is correct. The only possible difference between the .308 & 30-06 is the reduced friction of the 1/2" shorter .308 cartridge as it is stripped from the en-bloc clip as compared to the longer 30-06 cartridge.

Regards,
hps

 

[Jeremy2171]

For the record....the OP has said nothing about reloading and I think some of the responses here are pretty overwhelming (and accurate information wise) to someone who only asked about "milsurp" ammo.

So in short..."yes" your rifle is safe to shoot NATO spec ammo in. If you were to start reloading it will open up another can of worms that isn't neccessarily specific to the Garand but to reloading in general. Garand specific reloading questions should probably be in a post by themselves to avoid confusion with "new guys" who just want to know whats "ok" for their rifle.

 

[Slamfire]

To illustrate the importance of the above statement, had a friend who is a very experienced highpower competitor and reloader who wrecked his match grade .308 M1 Garand using the same handloads he has used for years when the rifle slam fired only partially in battery. Bent his op-rod, blew extractor/ejector out of bolt and rounded the receiver locking lug recess about 1/8" showing the bolt lug had barely entered the recess and was not in battery at the time the slamfire occured. He received a cut on the forehead and had a little problem with his trigger control for a while afterwards. Fortunately, the rifle, and his shooting ability have since been repaired

I am curious if you know the primer he was using. The fact his rounds were overally long lead to a delay in bolt closure. One match 30-06 Garand that I own, slamfired with Federals. The cases turned out to be a little fat and a little long. Unfortunately, the lugs did not engage in this incident. It blew the back end of my receiver off. I particularly remember the anxiety I developed, with blood pouring off my face and shattered shooting glasses on the bench, in the time period from the bench, to the truck mirror, to see if I still had a face.

It only takes one out of battery slamfire to make one very particular about reloading techniques.

 

[hps1]

I am curious if you know the primer he was using. The fact his rounds were overally long lead to a delay in bolt closure. One match 30-06 Garand that I own, slamfired with Federals. The cases turned out to be a little fat and a little long. Unfortunately, the lugs did not engage in this incident. It blew the back end of my receiver off. I particularly remember the anxiety I developed, with blood pouring off my face and shattered shooting glasses on the bench, in the time period from the bench, to the truck mirror, to see if I still had a face.

It only takes one out of battery slamfire to make one very particular about reloading techniques

Yes, he was also using Federal primers. I used Federals for years without incident, but switched to CCI due to their slightly harder cup. The 34 is even a bit tougher or so they say.

If the round (or should I say the primer) stops short of full battery (for whatever reason), the bridge in the receiver may not keep firing pin from igniting the primer and the harder milspec primers are just one more layer of protection the handloader can employ.

Slamfire, hope you suffered no permanent injuries; that's scary!

I apologize if I got off OP's subject a bit, but there are many new Garand shooters now and what with milsurp ammo getting harder to find, many have, or will resort to reloading, making this a bit more pertinent.

Regards,
hps

 

[Slamfire]

I have talked to a number of gentleman who had slamfires with their reloads in Garands and one in a M1a. The one common thread was Federal primers. It is the most sensitive primer out there. Which is consistent with my theory that primer sensitivity is the primary cause of slamfires.

I had two slamfires in Garands with Federals that caused damage to the rifle. The last one the back of the receiver came off. I had one closed bolt slamfire with a Garand using Federals. I was using a SLED, but still the round discharged. This was during the standing stage.

The old nickel plated WLR was a great primer, but it has been redesigned to make it more sensitive, and that is not a good thing. Winchester made the redesigned primer brass colored. It is thinner and more sensitive. People are reporting slamfires with the new primer. http://www.thefiringline.com/forums/showthread.php?t=250855

 

[Oohrah]

Sorry can't agree about slam fire and sensitive primers. Most
likely primers incorrectly seated to where they are high are the
bad guys! As with all semis, the Garands operate at or about a level
with a certain powder burn range and bullet weights if in 308 or 30-06.
In the 30-06, bullet wts. from 150 to l62 and a slightly heavier target.
When converted to 308, the same area of bullet/pressure range/powder
burn rate must be kept around the same. Heavy bullets/slow burn powder
will batter with the stock set up. I don't know if a change out in op
springs and adjustable gas cycliner plug like the 14s could make a difference.
However, the best way to stay toruble free is to stay within limits of it's
design. I have owned and fired Garands since the late 50s. Of the five
that I have now, one is a target mode Navy I believe, in the 308 chamber-
ing. It has been feed milsurp of many kinds along with reloads mostly
around 147 to 150 grn bullets with nairy a hickup or failure in any way. Never
been present or had hang fire or bolt slam fires except for a SKS that
I do not have a clue except a suspected bolt that grease in a bolt allowed
the pin to remain fixed in a forward postion. Was not a choice for a battle
weapon, so not much attention was payed.

 

[Slamfire]

Sorry can't agree about slam fire and sensitive primers. Most
likely primers incorrectly seated to where they are high are the
bad guys!

The high primer theory does not explain slamfires with factory primed ammunition. Such as reported by this Gentleman.


http://forums.accuratereloading.com/eve/forums?a=tpc&s=518103&f=2511043&m=348101466&r=615101566

“In the summer of 1968 or 69 the Atlantic Fleet Rifle Matches were plagued with slamfires using .308 Match ammo. Seems a terrible long time ago, and I still get upset about it because I lost my best and only chance to leg out on that cartridge. I was in the first relay at 500 yards (not 600 because the Annapolis range only went out to 500), and someone else popped off the first slamfire and dumped a bullet into Chesapeake Bay. I think I was the second or third to do so, and dropped my score from winner to first leather. The range officer did not allow a refire for any of us in first relay. By the second relay, the ammo malfunction was quite evident, and refires were given, but nothing was done for those of us in first relay. Slamfires popped all afternoon, was not a pretty sight. On examination, and believe me everyone was looking at ammo that day, the decision was a batch of overly sensitive primers. I guarantee, a slamfire can run your entire day!!!”

You have attempted to explain away your SKS slamfire by blaiming grease, or something else. Is your SKS a Chinese SKS?

 

[enichols]

Thanks for all the info, guys. As Jeremy2171 said, my question was directed more towards using 7.62 nato surplus ammunition in my .308 Garand, not reloading for said rifle. Unfortunately, being a masters student I have no time for reloading (or space in my apartment), otherwise I would definitely do so.
However, these responses have all been thoughtful and informative, so thanks again for the info.
-Nic