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M1 .308

2129 Views 11 Replies 10 Participants Last post by  rc
When my brother first came to Viet Nam they had M1s that shot .308. Were these chambered in .308 or did they use inserts to make them shoot Nato .308
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Actually there were no .308 M1's. The designation was/is 7.62mm which is a slightly different chamber. The .308 designation comes from civilians who reference the very closely designed Winchester chamber which usually will interchange ammunition both ways. Most enthusiasts use the .308 designation out of habit, but the military used only 7.62mm.

The 7.62mm M1's were predominately Navy issue. The Navy used both methods, the chamber insert and chambered barrels. A knowledgeable GI could tell which he had by knowing drawing numbers. The insert barrel would still retain the old cal. .30 drawing number. The chambered barrel would have an entirely different drawing number.

The standards were if the barrel's chamber and bore were new/perfect in every way, a sleeve was used. If there was anything wrong at all, slight corrosion, burr, worn, etc., the rifle was rebarreled with a new 7.62mm barrel.

Springfield Armory, in 1963 thru 1964 did some tests comparing the Navy Sleeve with chambered barrels. SA's foound many problems with the sleeve method. One day I will consolidate the findings and publish it for all to see.

There are civilian M1's in .308. It is my understanding that some companies offer either .308 or 7.62mm barrels on the commercial market.
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Thanks for the information Bill.

At the time I was there We did not know that there were inserts. We were only 19-20. In fact we only knew how to clean out rifles and had to ask armory what to do if it failed. At the time I was amazed that they had M1s in country. When he showed it to me I could not believe it. We were both In Viet Nam at the same time. But our outfit had M14s.
M1's in 7.62 - I have one

I own a NM M1 in 7.62, that I bought in 1970. Story goes it was made by USAF for competition shooting. All I can say for sure is it has always shot better than I can. It has a 7.62 barrel, no insert.

One of the 30/06 to 7.62 insert kits the Navy used on Garands.
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That one shown is a commercial copy that was advertised in the Shotgun News years ago.
Geez, you folks are really "on it"! Keep the excellent information coming!


Tom O.
One problem with the inserts was that they would occasionally eject with the shell casing.
I have one and also the block so that only 7.62X51 ammo, not 30.06, can only be used.


I tried one of these inserts on two different M1 Rifles and neither would chamber a 7.62mm or .308 cartridge with the insert in the chamber.

My good old M1917 Rifle, however, loves the insert and at a dime to 12 cents a shot for good surplus 7.62mm (in large lots) it's much cheaper than quarter a shot M2 Ball.

There were a bunch of "Navy" 7.62mm Garands sold in Shotgun News a few years ago. The ad never said "which Navy" they were from. I suspect it wasn't ours.

-- Chuck
CMP has announced they have several dozen 7.62 M1's that they will be auctioning off. Read more here..

Chuck S said:
There were a bunch of "Navy" 7.62mm Garands sold in Shotgun News a few years ago. The ad never said "which Navy" they were from. I suspect it wasn't ours.

-- Chuck
I still have the ad copy from "The Dealer Warehouse". The ad stated US Navy, but a phone call to get marking information revealed that they didn't want to talk about how the barrels were marked. I finally saw one and the barrel was marked "7.62mm NATO M11". Not correct for US Navy. What they were or are, I have no idea, I just know that they are not Navy 7.62 M1s. FWIW.
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