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    M1 Garand Headspace

    Guys,
    I have recently acquired a M1 Garand from a friend who recently passed away and wanted me to have it. It was purchased about the same time I bought mine close to 30 years ago both rifles had shot out barrels and were replaced with a match grade by the same smith. I’m not sure what the brand is I’m sure he told me but that’s close to 30 years ago. They are black not a GI style no marking any were that I can find but both shoot very well. My rifle is SA USGI receiver dated to 12/1942 was a blue sky import and been through armory rebuilds so there not much original on it. I paid whole $130.00 for it and I’m sure it would sell for a lot more but I plan to pass it on to my boys. Looking back I wish I would have hung on to that old barrel I would bet it was original.
    This new rifle has NAT’l. ORD. INC. S. EL MONTE CA. on the receiver with a 56XX S/N. I didn’t know what this company was until I did an internet search and found that article on the 30carbine site. I was somewhat concerned after reading the article on the quality of this receiver. It appears to be from a short run of investment cast receivers they were looking to produce Garand rifles with rather than the welded ones they were using. The rifle has what appears to be an unissued GI stock and other than the barrel/receiver is made up of what appears to be mostly new unissued parts judging by the minimal wear on them.
    After I took the rifle out to the range and ran some mild reloads through it I checked the cases with a Wilson case gauge and found them out of spec by .010-.012 sticking above the gauge surface. So I pull the rifle down stripped the bolt and checked it with my Foster 30-06 Field gauge. It will not close on a field gauge but is closer than I would like, I can stick a .032 feeler gauge between the lug and the receiver. Is it that common for a smith to ream the chamber that loose? I’m thinking I may be looking for another receiver, what you folks think? Thanks…John

    #2
    It could any one or combination of several things. Nat'l Ordnance wasn't known for top-end workmanship. The bolt lugs could be worn, poor final machining on the receiver, or receiver stretch immediately come to mind. As long as the bolt doesn't close COMPLETELY on the field gage, you're good to go. As for the elongated cases--they're stretching to fill the chamber when fired, a totally natural occurance, especially with a maximum chamber. Shoot it, enjoy its history, and remember your friend. Check the head space at least on a semi-irregular basis. If / when the bolt closes on your field gage, it might be time for a new bolt or barrel swap, or both.
    Enjoy.
    Jon

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      #3
      Thanks Jon for your response it was appreciated! I been doing some checking and I think I may have run the issue down. I'm trained machinist retired now and started checking a couple of dimensions. As you say Nat'l Ordnance isn't know for high quality and my friend was told this rifle was a pre-production test unit so it might have had the heck shot out of it with hot loads to test these receivers. I decided to check the size of the opening that the rh bolt lug drops into and compare it to my USGI receiver. I found that the Nat'l Ord opening was .020 wider that the USGI which might explain the case stretching with the bolt moving back that much farther when the weapon fires. With the hammer cocked that bolt moves back and forth noticeably more than the USGI one. I would like to take it to a shop some time and have it Rockwell tested to see if it's properly heat treated. Being investment cast if it's to soft it would tend to wear more quickly or possibly stretch and that might be whats going on I can't imagine that smith would have reamed the chamber that loose on a new barrel. Just a thought.

      Here are a some pic's of the stock any idea who made it? I cannot find any markings...
      John

      Comment


        #4
        I too, am a retired journeyman machinist/tool and die maker. Small world, huh?
        From what I can see, your stock appears to be a SA stock. Are there any stampings on the left hand side of the stock at the approximate rear of the receiver? If there are, and you can see what they are, a more definitive answer will be easy.
        As an aside, a friend of mine sent me an article today from another forum about an M1 that was destroyed by a reenactor using blanks. It was a cast receiver made by Lithgow in Australia. Long story short, there was apparently a barrel obstruction of some sort and when the next round went off, the excessive pressure sent the bolt through the receiver heel and broke it (the heel) off. The shooter had shrapnel in his face and one helluva black eye. Damn good thing he had his shooting glasses on. Just saying. It's a testament to the cast v. forged arguement. Be careful with that Nat'l Ordnance rifle. Maybe make a wall hanger out of it.
        Jon

        Comment


          #5
          Here's the link to the story. Notice the crystalized material. I think the damage was accumulative over time and it just finally let loose. The bolt does hit the inside of the heel with each and every firing. THAT'S why it's important to check/replace the op rod spring on occasion. ALL springs eventually fatigue and fail.
          https://www.ar15.com/forums/Armory/J...gram/6-517822/
          Jon
          Last edited by TJT; 11-12-2020, 04:11 AM.

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            #6
            I agree it's an SA stock. It has the slim profile of SA. Most likely a replacement stock with no proof firing stamp. Walnut too, nice condition.

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