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Feeding problems with M1A

Discussion in 'Rifle Country' started by uneasy_rider, Dec 18, 2007.

  1. uneasy_rider

    uneasy_rider Member

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    I can hand cycle rounds through my M1A with no problem. However, I am having trouble when shooting. Sometimes, the spent cartridge is not ejected from the rifle at all. I don't think the bolt even opens when that happens, but its hard to tell. Sometimes, the spent case is ejected, but a new round is not fed into the chamber. I can't tell if the bolt is going back far enough to pick up a new round. I think it might be short stroking. About 20% of the time, it will eject a spent case, and pick up a fresh round like its supposed to.

    This was the first time I have shot this rifle in over a year. I have never cleaned the gas system, but have field stripped the rifle and cleaned it when I put it up last year. It has about 500 rounds max through it, and has never had a cycling problem til now. I am using USGI magazines.

    What is my problem?
     
  2. Andrewsky

    Andrewsky Member

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    What ammo are you shooting?

    Do you have a scope mount?

    What make is your extractor?

    Is your gas valve completely in the open position?

    Clean your gas system.

    What kind of lubrication are you using?
     
  3. uneasy_rider

    uneasy_rider Member

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    I am shooting reloads that work fine through my FALs. They are 150g FMJ's loaded over 43.5g of Winchester 748, to give a chronographed velocity of 2600 fps.

    I know people poo poo reloads here, but these are well made and I do not believe are part of the problem. I plan on trying some Winchester 7.62x51 NATO surplus over the weekend, but don't expect it to make any difference.

    My extractor is whatever Springfield Armory puts on their M1A's.

    I am not sure what position my gas valve is in. The gun worked flawlessly the last time I used it, which was over a year ago. How do I tell what position it is in ?

    I lubed it when I put it up a year ago, using Lubriplate.
     
  4. Andrewsky

    Andrewsky Member

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    The valve should be straight up and down; perpendicular to the barrel.

    Try out that NATO stuff.

    Springfield extractors are notoriously bad. You might have to replace yours with a Fulton extractor. They're $35 but Fulton is having a 12% off sale right now. You can use the M14 combo tool to take the bolt apart. Degrease the gun and apply tetra grease.

    And clean your gas piston, but do not lubricate it. Make sure you have the appropriate tools for disassembling the gas system so you don't put any torque on the barrel, etc.
     
  5. uneasy_rider

    uneasy_rider Member

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    What tools do i need to disassemble the gas system?

    I have heard lubriplate is what the military uses to lube the M14. Do you think Tetra is better?
     
  6. Slugless

    Slugless Member

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    I suspect it's your gas system.

    Pick up the rifle, hold it in the vertical position muzzle up. Now flip it over so the muzzle faces down.

    Does the gas piston move freely? If it doesn't move it badly needs cleaning.

    That said, I have a similar problem with my M1A. With Lithuanian ammo, it ejects fine but seems to be short stroking - either failure to feed or failure to go into battery.

    I cleaned the piece and cleaned the gas system well (even though the piston moved) with q-tips and scotchbrite. Also I tightened up the gas plug real well, it wasn't torqued properly. This reduced the FTFeed to 5% from 20%.

    I then ordered gas system cleaning materials from Sadlak Industries. Nice kit.

    I've not shot it since because of the deer season rush at the rifle range. Lots of yahoos & distractions. I plan to shoot it over the holidays.

    For me it seems to be a combination of ammo + dirty gas system. My rifle also had sat around for a couple years & when I brought it out it seemed over lubed.

    There's some other things to look at, too but first:

    *clean the rifle
    *use lubriplate only on the parts of the rifle where it is specified
    *clean the gas system thoroughly w/drill bits, don't lube it at all
    *check the gas valve - the slot in it should line up in the same direction of the gas flow
    *check the gas port in the barrel for obstructions
    *try some different ammo
    *search on M14-forums for similar problems (you'll probably find my post)

    Let us know what happens.

    *Edit - whoops, other posts in the meantime. Tetra is excellent, I highly recommend it. I use Tetra, not lubriplate. Use the combo tool on your gas system.
     
  7. uneasy_rider

    uneasy_rider Member

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    I can hear the piston moving when I have the bolt locked back, but not when the bolt is forward. Is that normal?

    Where can I get detailed instructions on how to clean the gas system?
     
  8. Slugless

    Slugless Member

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    {deleted. that was so stupid I'm embarrassed. RTFM.}

    Send me a PM for some cleaning instructions.
     
    Last edited: Dec 18, 2007
  9. GunTech

    GunTech Senior Member

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    The piston should move with the bolt back, and bolt when the bolt is forward. Perfectly normal. When the bolt is forward, the op rod is resting against the piston.
     
  10. GunTech

    GunTech Senior Member

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    To disassemble the gas system, you need a combo tool or a 7/16 wrench. Just unbolt the gas plus and the piston should fall right out. I use a set of Sadlak drills to get to crud out.

    http://www.sadlak.com/si_tools.html
     
  11. GunTech

    GunTech Senior Member

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    Are you using commercial or military brass? In military brass, 43.5 should give about 2740 fps (LC). In commercial brass like WW, you need to kick it up a couple of grains.

    Try this: Insert one round in an empty magazine and fire. Does the bolt lock open?
     
  12. W.E.G.

    W.E.G. Senior Member

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  13. Z71

    Z71 Member

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    When the bolt is foward in battery on an M14/M1A rifle, the op-rod is forward against the gas piston. Have to lock the bolt back to hear the gas piston clunk back and forth when checking for a stuck piston.

    I've had my Polytech M14S rifles work fine with the gas piston stuck enough that it wouldn't move under it's own weight.

    Almost sounds like a blocked or mis-aligned gas port. Better check out the gas valve setting, and possibly the assembly of the gas piston housing and retainer parts.
     
  14. Slugless

    Slugless Member

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    Here's some advice I received:

    Does anyone know the best drill bit size? Or another method/alignment gauge?
     
  15. Wild Deuce

    Wild Deuce Member

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  16. uneasy_rider

    uneasy_rider Member

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    I am using once fired Lake City military brass bought from GI Brass and sized with RCBS small base dies. I get an average of 2600 fps from both the M1A and the FAL. I am loading to an OAL of 2.800", which is about maximum length that will fit in the magazines.

    Do you think 2600 fps is too slow to cycle the M1A mechanism?
     
  17. GunTech

    GunTech Senior Member

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    That load should run. Do you have the same issue with all magazines? Have you tried milsurp ammo?
     
  18. Andrewsky

    Andrewsky Member

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    Make sure that when you take your gas piston out you don't drop it on a hard surface.
     
  19. Winger Ed.

    Winger Ed. Member

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    Darn, that's frustrating.
    I thought the gas piston thing would have gotten ya fixed up.
    If ya can hear it sliding back & forth- with the bolt open- its fine;
    and I wouldn't take it apart if it was mine.

    You're doing everything right,
    and your ammo is plenty hot enough to make it cycle.

    The only other 'shot in the dark' I can think of is your magazine
    just 'doesn't fit'.

    Can ya get, and/or try- a real, genuine, un-damaged, clean, black, USGI magazine for it,,
    and not just another after market one?

    (I've had the gray or silver aftermarket M14 magazines just give me fits--
    Right up until I put them up on top of the target board and shot them with
    a .50BMG----several times)

    If the feed lips on top of the mag. are screwed up:
    they'll present the next round improperly to be fed into the chamber,
    and maybe even drag on the bottom of the bolt.

    .
     
  20. Chris Orndorff

    Chris Orndorff New Member

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    I had a similar problem with my M1A; failure to extract. My rifle was clean, properly lubricated and the gas system was clean and dry. I had a GI extractor in the bolt. I finally sent the rifle back to SAI and they replaced the bolt with a forged item. It's run perfectly since then.
     
  21. Andrewsky

    Andrewsky Member

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    You might want to grease your bolt roller as well.

    Your op rod probably isn't bent...hmmm, I'm just trying to think of everything...

    Maybe go to 44mag.com and buy a CMI mag and tell us if that helps. These are current issue USGI mags. I've got 11 of them they're good stuff.
     
  22. wayne in boca

    wayne in boca Member

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    If your gas piston and gas plug have encrusted carbon inside them,They are effectively smaller than they should be,and thus have less volume for gas.This will cause exactly what you describe,short cycling.Get the Sadlak drills and gas cylinder wrench and clean them out.Then grease the rifle and try her again.
     
  23. uneasy_rider

    uneasy_rider Member

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    Why would a mag cause a complete failure to extract?
     
  24. Slugless

    Slugless Member

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    uneasy,

    I think the mag advice is more about the failure to feed symptom. GunTech's advice about 1 round in a mag is good.

    FWIW, I drilled out my piston & found carbon inside. Not a lot but it seemed to collect in a couple rings inside the piston. A carbon ring could act as a restriction and affect the piston movement more than just the volume of carbon itself.

    I suspect Wayne is right but I think it's weird that two of us w/500 round rifles put up for a year have nearly identical symptoms. I figured the M1A was more rugged than that. A GI with an M14 doesn't exactly have mail order access to Sadlak on the battlefield.

    Hopefully it's not a misaligned gas port. I'd like to know how to check the alignment. A pipe cleaner goes into it fine, so did a very small diameter allen wrench. But that's just testing for gross blockage, not a restriction due to a little misalignment.
     
  25. Slamfire

    Slamfire Senior Member

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    No, that is an excellent velocity to be at for your M1a. The rifle will cycle at even lower velocities.


    Sounds like you are doing everything right.


    I suspect you have a gas system problem or an extractor problem. As others have said clean out your gas piston. I do not recommend removing the gas cylinder because each time you do, it gets loose on the splines. You can clean out the cylinder with bore cleaner on patches.

    Don't forget to put "antiseize" on the threads of the the gas lock screw. You can get that at an auto store. [​IMG]

    If you have never cleaned your gas piston then it is entirely possible that your rifle is cycling too fast to pick up a round.

    Just buy an extra extractor and ejector spring. I would recommend disassembling the bolt and cleaning those out, just to make sure.
     

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