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  1. #1
    Join Date
    Dec 1969
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    Winston-Salem, NC
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    68

    Default Mosin Nagant m91/30 Extraction issues

    My buddy has a 1927 Ex Dragoon m91/30 that has a horrible case of sticky bolt. We can only get one round of russian steel case surplus shot, then you have to hammer on the bolt to get it to open. We thought it was just cosmoline stuck in the chamber, so we scrubbed and scrubbed, but has not helped. Same thing happened. He soaked in diesel, scrubbed again, and this time we used some PPV brass, but the same thing happened. I measured the bolt head, and from the back to the bolt face is only 1.41, mine are 1.445, 1.45 and 1.47. Eureka I thought, he has a headspace issue and this is causing the case to expand too much. We have ordered the Okie gauges just to rule that out. But I don't think that is the problem. With every bolt head, the same thing happens, BUT with the 1.445 it only takes one swack on the bolt to get it to extract. i measured the brass before and after shooting. At the rim, before was .486, after was .488. 1/4" down from that went from .4845 to .488, 1/2" down from that went from .471 to .477!! Is the chamber just WAY out of spec.
    There is also this other problem.....I kept cycling a piece of brass that I shot out of it, from full cock(had to beat the bolt down) to just before it hit the extractor knocks it out, and it is making some SEVERELY scrapes in two spots. Is it short chambered?? Do we need to find another barrel, find someone with a finish reamer, convince him to just give it to me so he can be done with it??? Click image for larger version. 

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ID:	708712I am currently on my 6th, 7th, and 8th mosin and have never had this much problem.
    ANY experience or ideas are appreciated.
    Last edited by arjppj; 10-17-2013 at 06:57 PM.

  2. #2
    Join Date
    Jun 2013
    Location
    south carolina
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    151

    Default

    could be the bolt body, id wait untill the headspace gauges come in then use them and then try to figure the issue as no point in trying to fix the issue right now if the go gauge wont even work when you get them in. have you tried switching the whole bolt out? if not give that a try and see what happens.
    Looking for mosin 91/30 bolt and floorplate KE9841!

  3. #3
    Join Date
    Dec 1969
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    Winston-Salem, NC
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    68

    Default

    I cycled one of my bolts in his rifle with a spent case, it felt the same, but I did not shoot one with the entire bolt.

  4. #4
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    Jun 2013
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    south carolina
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    Default

    hmmm, i wonder is the extractor making a groove in the bluing in the relief cut that is on the side of the barrel? wont hurt to put a 20 gauge brush on a cleaning rod, then chuck it in your drill and use some polishing compound to really clean the chamber. can you put a round fully in the chamber by hand? or does it stop somewhere? if it stops i would suggest looking very carefully inside the chamber to see if theres part of a broken shell stuck in there. or the face of the chamber has a burr as you are getting scoring along the case and only goes so far up. maybe take a case color it with a sharpie and put it in the rifle and slowly close the bolt until you feel not normal resistance and remove the shell which should tell you where the burr would be.
    Looking for mosin 91/30 bolt and floorplate KE9841!

  5. #5
    Join Date
    Oct 2013
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    2

    Default

    hey guys, I'm arjppj's less knowledge friend, the one that wound up with this little beauty...
    opie, we've gone after the chamber with a drill chuck'd 20 gauge brush twice now. First time using just an ample amount oil and the second time using JB's non embedding bore compound... not much difference really from first firing. We can put an unfired round in the chamber no problem and the bolt will close and then extract the unfired very normally. Its only with the spent case that it won't/barely go back in. I haven't done the sharpie test, but it doesn't appear to be marking up the case until after the round has been fired.

  6. #6
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    Jun 2013
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    south carolina
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    Default

    ok now we are clear, what is happening is when fired the case expands and with tighter chambers rounds can sometimes be hard to extract. have you tried to fire any brass cased ammo out of it? if so fire a round and look at the case very closely and it will basically make an imprint of your chamber and then look and measure an unfired brass round and the fired case. i know my rifle it dont like to put fired cases back in the chamber but no issues with extraction. you might need to work the jb;s some more and visually check(with small mirror) the chamber. i bet if you try brass cased ammo you wont have extraction issues.
    Looking for mosin 91/30 bolt and floorplate KE9841!

  7. #7
    Join Date
    Nov 2008
    Location
    WY
    Posts
    173

    Default

    Original post said they tried PPV brass and got the same result, I assumed that was brass-cased.
    Have you tried inserting his fired brass into one of your Mosins? Or tried some of your fired brass into his rifle?*
    The picture looks like a burr in the chamber, or wildly oversized chamber near the base of the cartridge, causing the brass to expand past its elastic limit.
    7.62x54r headspaces on the rim of the cartridge, so a headspace gauge may not tell you much about the length of the chamber.

    *I'm using "brass" as a generic term for cartridge case, not just brass cartridge case.

  8. #8
    Join Date
    Oct 2013
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    You are correct, we've tried multiple samples of steel cased military surplus as well as brass. The brass made it bearable for your palms to slap the bolt open, but still required a significant slap. I just tried inserting a case fired by the gun in question into my '38 tula, it will chamber with a slight bolt slap required to get it to fully close.

  9. #9
    Join Date
    Dec 1969
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    Winston-Salem, NC
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    Default

    When we fire the round, then try to extract it, is when it scratches the brass all the way around. After putting the spent round on the bolt and cycling a few times is when is gouges the brass, as seen in the picture. There is NO problem putting in an unshot round and pulling it back out. According to the measurements in the Hornady manual of the case, and the after measurements of the brass case, it is swelling to the max size listed at the rim and above the size listed at the shoulder. It seems that it is swelling way past safe dimensions where you experience head separation on the brass.

  10. #10
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    Nov 2008
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    WY
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    Default

    Quote Originally Posted by Hodadical View Post
    You are correct, we've tried multiple samples of steel cased military surplus as well as brass. The brass made it bearable for your palms to slap the bolt open, but still required a significant slap. I just tried inserting a case fired by the gun in question into my '38 tula, it will chamber with a slight bolt slap required to get it to fully close.
    Is the bolt slap on your '38 Tula required to snap the extractor over the rim, or to fully close the bolt? What happens when you extract the case fired in the ex-Dragoon from your '38 Tula? Does it extract easily, or do you have to beat it open? If the latter, is the case scratched at the base like the ex-Dragoon's case in the picture?

  11. #11
    Join Date
    Jan 2009
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    1,764

    Default

    is the chamber smooth ??...sounds like a rough chamber somewhere holding the brass/case after expansion.

  12. #12
    Join Date
    Dec 1969
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    Winston-Salem, NC
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    the tula fired brass will chamber in the ex dragoon easily, but trying to pull it out you can already see the ring around the brass near the rim. A piece of brass fired from the izzy can go into the tula, you just have to force it almost like you are sizing without using lube. Our next process is to get a small dental pick and play around with the chamber to see what we can find, using brass to see the problem areas. It just baffles me is why there is a ring all around the brass? A burr is one thing, but a complete burr around the entire chamber is strange. And as to WHY the brass is swelling so bad? My other rounds may swell .001, but this thing is jumping up by .006 in some spots. That just ain't right!

  13. #13
    Join Date
    Dec 1969
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    235

    Default

    I used a round bit of sticky back DA sandpaper cut into a tiny circle then cut from the edge to the middle so I could fold it into a cone that would stick to itself and be sticky on the inside. If that's confusing picture a Vietnamese cone hat that is sticky on the inside. Stick it to your pinky and push it up inside to the back of the chamber opening, the cone should be cut so that its too big to go inside the chamber. Now twist it around back and forth pressing it against the back of the chamber until your pinky feels like its going to fall off, that will deburr and ever so slightly chamfer the opening to the chamber.

    Its fairly normal to scratch up a spent casing running it in and out because the opening to the chamber isn't perfect on these from the factory and the case has already expanded to max out that diameter. For that matter the chambers on these are pretty crappy a lot of the time too, they weren't reloading and I'd imagine the specs were fairly loose. I have at least one gun with the circular cutting marks from the chamber boring still quite visible in a large area inside the chamber, but its a low spot so it doesn't catch super bad.

    Never really looked at mine so it might be totally normal, but that does look like kinda loose headspacing based on where the scratches stop, if the round just wasn't seating all the way in the chamber due to obstruction you wouldn't be able to get the bolt closed. Those gauges will be helpful.

    Also I had a rifle that literally had cooked in cosmoline in the chamber that was basically like epoxy and was almost chemical proof and couldn't be mechanically cleaned. When you fired a round the expanding hot round basically glued itself in place. I didn't believe it was there till I took a whole boiling tea kettle and dumped it down the chamber end (gun totally stripped) to let it run out the muzzle. Keep going until the metal is so hot you have to use mittens to hold it even on the outside, it will almost instantly flash dry. Then quickly run a dry clean patch from the chamber out the muzzle, if yours is like mine it will come out with reddish brown gunk on it that wasn't there before the boiling water ran through it. Though its unrelated to this, I have also run steel bore brushes through mosins and suddenly the worn looking bore has nice sharp rifling again because it was just years of crap snuggled up to edges of the lands that softer brass brushes wouldn't dislodge making them look more rounded. Between that and the boiling you can get a bore cleaned pretty amazing.

    Those are my uneducated thoughts on things anyways.

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