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M1 Carbine: cracked gas block, what should I do?

Discussion in 'Gunsmithing and Repairs' started by Spug, Oct 11, 2017.

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  1. Spug

    Spug Member

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    So I've got an M1 carbine...

    ...yes, it's a Universal. But it's a very early one, built with GI parts and has a 4-digit serial number. I came into it after my dad died, and I don't really know anything about its history. I love carbines in general, and love the feel of the M1 particularly, as well as the Garand-style action, which I don't have in any firearm. But I have never fired it and don't know if my father did either. It has a cool leather scabbard for mounting on a jeep or motorcycle.

    IMG_2148.JPG

    I was aware that it hadn't functioned in decades, so I tore it down to see if I could figure out what was wrong. Two things that were readily apparent were that the gas block is cracked and the hammer is beat up. Despite the cracks as seen in the picture below the internal threads seem ok, as does the nut and gas piston. I haven't found a lot on the web to help me with this problem, but what I am thinking of doing is to squeeze the cracks together, perhaps with a sacrificial plug inserted in place of the castle nut to preserve the thread, and have someone TIG weld it up, leaving the hole open so that the gas port can be cleaned when necessary. So my first question is, what are the chances of success?

    Sorry for the really poor pictures, but you can see enough to get an idea of the problem. For those not familiar with the M1 Carbine, there are two cracks in the picture of the gas block, not three: an additional slot is machined aft of the clean-out hole.

    IMG_2073 - Copy.JPG

    The other issue is the hammer, which looks like it has sustained some real hammering (sorry). So I'm wondering if the carbine experienced a slam fire malfunction that led to both issues. Least likely, but most potentially problematic, is that somebody modified it at some time before it came to my dad.

    IMG_2076.JPG

    I've got a brother who is hugely into WWII history and has visited Normandy many times. He's made it known to me that he'd really like the carbine, but I doubt he'll ever do anything but fondle it. I'd like to see it repaired to operable trim, but I don't know if it can be done at a reasonable price. What do you all think? Is it a simple matter to have a 'smith weld the block up, and perhaps the hammer wear is not a big deal (or I can get another hammer) or is this a potentially fraught project and I should just pass it along to my brother and forget about it ever being a shooter?
     

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  2. Sunray

    Sunray Member

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    "...have a 'smith weld the block..." No. That's more than just a crack.
    Unless you want to go to the expense of rebarreling a Universal, it's toast. Gas blocks on Universals were welded on, as I recall, but you can't get another anyway. Gunparts bought up all remaining Universal/IJ parts, years ago, and are showing barrels as being out of stock. No gas piston nuts either.
    $23.65 for a hammer. Kind of moot without a barrel.
    Best tell your brother than a Universal has nothing whatever to do with any issue M1 Carbine(or M1 Rifle) too. Tell him to find a Plainfield. Or buy one in the new production Inland's.
     
  3. greyling22

    greyling22 Member

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    Would a gi barrel not fit? On the early ones they'd take most all gi parts right?
     
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  4. lemaymiami

    lemaymiami Member

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    Gas block woes (cracks, etc.) pretty much can't be repaired successfully (with a few exceptions that lure folks to try....). You're going to need a skilled gunsmith, familiar with Universals (if there is such a guy...) to carefully examine the carbine and advise whether a new Critierion barrel will work. If it will, then that's your course of action provided that the beaten up hammer wasn't caused by some other issue (if the receiver is badly worn or damaged stop right there and consider it a decoration instead of a firearm).

    In short by the time you get that weapon functioning (if it's even possible) you're going to be out some money.... and when you're done it will still be a Universal....
     
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  5. Gordon
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    Gordon Contributing Member

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    Ship it to this guy and see if he will fit a $215 dollar Criterion Barrel and fix the hammer ect.... Yo may be into it $500 all told but if he does it you will have an exquiste piece trhat will be very accurate and sweet.
    http://dgrguns.com/0-main-page-barrels.htm
     
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  6. pauli

    pauli Member

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    Give your brother the wallhanger, get yourself a good one to shoot.
     
  7. WessonOil

    WessonOil Member

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    I'd hang it on the wall since it has sentimental value.

    My first M1 Carbine was a latter model Universal that I got at a steal.

    It was a lot of fun to shoot and allowed me to take the money I saved and get set up to handload for .30 carbine.

    I then sold it at a substantial profit and bought a USGI Inland.

    I'd take whatever money you were going to spend to fix this up and apply it towards a USGI carbine.
     
  8. dfariswheel

    dfariswheel Member

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    Interesting modification on the stock, pistol grip removed.

    As above, the cost to rebarrel will be high enough as to give second thoughts.
    Which brings up the questions as to what to do with it...wall hanger, part it out, or bite the bullet and rebarrel.

    Some gunsmiths will not attempt to rebarrel a Universal due to the cast receiver.
    As I recall some of the Universal's had a void area inside the receiver that would cause it to crack if an attempt was made to remove the barrel.
    This void was an artifact of the casting design, not an accidental casting void. I never heard why they put it there.
     
  9. hdwhit

    hdwhit Member

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    The earliest Universals were indeed made with GI surplus parts (along with commercial reproductions as the GI parts ran out). As such, it should be a straight-forward matter of replacing the barrel. As others have already posted, Criterion barrels are available.

    As much as I love Carbines, I would not spend the money to try and rehabilitate this one. The damage to the gas block and the hammer are indicative of a prior owner repeatedly firing ammunition that was significantly over-pressure. The cumulative damage to the remaining parts of the gun would make me concerned that something else would be about to fail.
     
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  10. Spug

    Spug Member

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    Thanks for all the replies. I guess it's not what I wanted to hear, but that disappointment is better than plowing money into it to no avail. As I noted, it is a very early Universal, with the U.S. GI trigger housing, so it was made in the early years of the company. I don't know how to tell if the receiver is cast vs. forged. The area forward of the ejection port has a smooth machined finish and is inscribed U.S. Carbine Cal. 30 M1 (all in caps), while the rear portion, just forward of the sights, looks almost like someone took a wire brush to it, and is stamped Universal Hialeah Fla, so I wonder if the receiver is a GI product too, with the original maker ground off. The receiver itself does not appear to have much wear at all, to my eye. The groove that the operating slide runs through is still mostly dark with bluing. The only parts that look bad are the hammer and gas block. That block appears to be silver-soldered to the barrel, by the way.
     
  11. CapnMac

    CapnMac Member

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    Since it has sentimental value, I'd be sore tempted to remove the firing pin from the bolt, and JB Weld the bolt up wher the firing pin goes. I'd probably do the same to the gas block as well.

    Which you could reassemble as a wall hanger. Which would have the benefit of having an action that could be cycled, and would go "click" but not "bang."

    Thinking of posterity, I might also be inclined to go get a long elliptical lead fishing sinker and use a dowel to hammer that about halfway into the chamber, which would prevent chambering a round..

    Now of this is Bubba-proof--very little in life truly is--but might serve as good enough.
     
  12. Spug

    Spug Member

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    Thanks for the advice CapnMac, but I cannot envision myself ever doing any of the things you recommend. Cheers!
     
    Last edited: Oct 14, 2017
  13. 4v50 Gary

    4v50 Gary Moderator Staff Member

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    Hammer and gas block are trashed. See if you can buy a new gas block and have it installed.
     
  14. dfariswheel

    dfariswheel Member

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    All Universal receivers were cast steel, none were forged and no surplus receivers were re-marked and used.
     
  15. CapnMac

    CapnMac Member

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    Well that's the sticky end of the stick.
    As Sunray pointed out in Post #2, Universal gas blocs were welded on.
    So, a smith would have to torch cut the old one off. Then, the barrel would have to be ground to fit the replacement gas block, presuming one could be found short of buying another Universal of the correct era.
    Then, there would be the problem of the gas piston nut, which are out of stock. (Also assuming that the gas piston can be salvaged, too.)

    Which brings us full circle to looing at a brand new Criterion barrel with gas block, plus all the smith time to fit same properly. Which will likely be an exercise as OP describes this as an early model, so it's probably a dual spring model (with a slight outside chance of being a central, GI-style, spring, too.
     
  16. rondog

    rondog Member

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    I'd spend the money and get it rebarreled, new hammer, new springs, whatever else. It was your dad's. But I also love shooting those lil' rascals.....
     
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  17. NIGHTLORD40K

    NIGHTLORD40K Member

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    http://www.m1carbinesinc.com/carbine_universal.html
    Everything you need to know about the Universals in the link above.

    I have serial number 73xx, (as well as a '44 Inland)- great gun! I have replaced the aluminum trigger housing with a GI one from Amherst Depot. Took some slight hand fitting to the receiver, but all the small parts fit right in- including the Inland hammer I bought to go with it. You should have no problem fitting a GI hammer to yours.

    Mine had a Rockola recoil plate, and an Inland slide and mag release, but all the other parts were Universal made as far as I could tell. The hammer was in good shape, but was obviously cast- that's the only reason I replaced it. The other internals appear very well fit and finished.

    Sorry, but no. Mine is forged and machined, as are all Universals (even the later two- springed ones). The only other aftermarket forged receivers are the new JRA/Rockolas and the limited run SAs from the 90s.
    It is true, Universal never remarked any GI receivers. But their home production receivers are very well made and machined.
    Universalreceivertop.jpg Universalreceivertop.jpg Universalslidelock1.jpg Universalslidelock2.jpg
    Sorry, Mac, its the second half of production (after number 99k) that had the dual springs. These are the ones that had a bad reputation as they also had the hollowed out slide handle which cracks and lack the firing pin interference in the receiver bridge to prevent out of battery firing. Spugs is a 100% GI part compatible single spring gun.
    This is one of my very favorite guns and is within a tic of just as good as a GI carbine- especially a worn, high mileage example.
    I would have your bolt and receiver magnafluxed for cracks in case the piston failure was due to excess pressures- if they check out, go for a rebarrel. Imho, it would be worth it, especially as this is a family heirloom.
     
    Last edited: Oct 15, 2017
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  18. Spug

    Spug Member

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    Through a series of fortunate circumstances I found a very local gunsmith, who sent it to a trusted welder for micro TIG welding, and cleaned up the weld, reblued, retapped and staked the castle nut. It looks great and I fired one 15-round magazine through it today. It shot great and gave me great joy. Threw the empty brass just a few feet behind my right shoulder. I field stripped and cleaned it and it looks good. I'll keep my eye on it in case any new cracks appear, and I intend to put a few rounds down the barrel.
     
  19. FROGO207

    FROGO207 Member

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    Some times knowing a guy that knows a guy that can pull off a good repair can be a deal changer. Glad they got you fixed up. I have one of the earlier ones as well as my grandfathers Inland. I also have a pair of 30 Carbine Blackhawks to go with them. They are a hoot to shoot IMHO.
     
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  20. NIGHTLORD40K

    NIGHTLORD40K Member

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    Great news! Btw, can't beat Seller and Bellot carbine ammo, runs about .45/round, burns very clean and shoots great! The Armscorp stuff is not bad, either, but seems to run a bit dirtier. Sometimes I come across Remington soft point hunting rounds- nice ammo, but I'm not sure if its still in production.
     
  21. Jim Watson

    Jim Watson Member

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    That's just great. About anything can be fixed if you can find the right people and are willing to pay for it.
    If it weren't a family heirloom, you'd probably have been better off to part it out and sell the real USGI bits and pieces.
     
  22. Jim K

    Jim K Member.

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    Making a new gas block is not exactly rocket science, but will not usually be in reach of the average home hobbyist,so will not be cheap. If you are considering that course, it might be best to consult a general machine shop but bring only the gas block and invent a name not involving guns ("part for a high pressure pump" is a favorite) the reason being that many shops are afraid to touch guns for reasons of liability, laws, etc. Even if they know what it is, they don't know "officially".

    Jim
     
  23. bluejeans

    bluejeans Member

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    Glad you did t let anyone talk you out of a decent gun...

    Edit: removed the rest as I realized it could sound demeaning of Some advice given here which was not my intent; there are many more knowledgeable than myself.
     
    Last edited: Mar 15, 2018
  24. fallout mike

    fallout mike Member

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    Be careful with that thing. I've got a thread on here from a few years ago about a Universal that went KABOOM on me. And it had not been even been "patched up".
     
  25. NIGHTLORD40K

    NIGHTLORD40K Member

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    Did you ever determine the cause of the failure?

    A loose piston nut (or piston housing failure) can spit the piston back at the shooter with dire consequences.
    Later Universals (made long after Spug's gun) can, theoretically, fire out of battery, which would also Kaboom them pretty good.....
     
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