Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: What are the characteristics of an over pressure round?

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    Dec 2011
    Location
    suburbs of Philly Pa
    Posts
    6,189
    Feedback Score
    1 (100%)

    What are the characteristics of an over pressure round?

    I know pictures are worth a 1000 words but I didn't take one and this has been bothering me for 2 days.

    On Saturday I took an AK class and everything was going great until the end. At the time I was using a Bulgarian 74 5.45x39 with wolf ammo.

    On the last drill everything was going fine till I got to maybe 3rd of 4th round when I had a malfunction. I was in prone with the mag resting on the ground. The bolt in the open position. I go to run the bolt thinking the previous case may have gotten caught. Nothing....bolt stuck to rear. I the go to remove the mag, a E. German bakelite, and it won't budge. The mag release is locked up. One of the mags on me was a Polish steel mag. I use it to smack the mag release and after a few good smacks it works and dislodged the release.

    One round falls out, the one that it had tried to chamber after the previous one was fired and the bolt closes but not all the way, and needs to be mortared to be opened up again. I notice the fired case is stuck in the chamber with about a quarter of it sticking out. The rim, where the extractor holds it, is torn off. I let the gun cool then inserted the cleaning rod and tried to tap out the casing using the steel mag. Didn't work. Since I had to be somewhere after this and still had an hour drive I didn't mess with the rifle, just threw it in the car and left. Yesterday I was too busy and later to pissed off to mess with it.

    The ammo was wolf with the grey steel casing and I can't remember if it was from the black flat box or the military classic square camo colored box.

    From what I can see the primer seems to have bulged out a little.
    I've never had issues with ammo in any caliber or style. I'm guessing that that round was overpressured?!?!!?

    What damage if any should I look for?

  2. #2
    Join Date
    Jun 2015
    Location
    Georgia
    Posts
    3,104
    Feedback Score
    2 (100%)
    Quote Originally Posted by Arik View Post
    I know pictures are worth a 1000 words but I didn't take one and this has been bothering me for 2 days.

    On Saturday I took an AK class and everything was going great until the end. At the time I was using a Bulgarian 74 5.45x39 with wolf ammo.

    On the last drill everything was going fine till I got to maybe 3rd of 4th round when I had a malfunction. I was in prone with the mag resting on the ground. The bolt in the open position. I go to run the bolt thinking the previous case may have gotten caught. Nothing....bolt stuck to rear. I the go to remove the mag, a E. German bakelite, and it won't budge. The mag release is locked up. One of the mags on me was a Polish steel mag. I use it to smack the mag release and after a few good smacks it works and dislodged the release.

    One round falls out, the one that it had tried to chamber after the previous one was fired and the bolt closes but not all the way, and needs to be mortared to be opened up again. I notice the fired case is stuck in the chamber with about a quarter of it sticking out. The rim, where the extractor holds it, is torn off. I let the gun cool then inserted the cleaning rod and tried to tap out the casing using the steel mag. Didn't work. Since I had to be somewhere after this and still had an hour drive I didn't mess with the rifle, just threw it in the car and left. Yesterday I was too busy and later to pissed off to mess with it.

    The ammo was wolf with the grey steel casing and I can't remember if it was from the black flat box or the military classic square camo colored box.

    From what I can see the primer seems to have bulged out a little.
    I've never had issues with ammo in any caliber or style. I'm guessing that that round was overpressured?!?!!?

    What damage if any should I look for?
    Almost sounds like you may have a bullet lodged in the bore...

  3. #3
    Join Date
    Dec 2011
    Location
    suburbs of Philly Pa
    Posts
    6,189
    Feedback Score
    1 (100%)
    Quote Originally Posted by georgeib View Post
    Almost sounds like you may have a bullet lodged in the bore...
    Couldn't tell but the cleaning rod goes all the way down. Just the tip sticking out

  4. #4
    Join Date
    Dec 2011
    Location
    suburbs of Philly Pa
    Posts
    6,189
    Feedback Score
    1 (100%)
    This is making less and less sense now.

    I went to try to knock out the casing. No luck. So I decided to check out the mag. At first I inserted a different mag and it locked in and came out fine. The I inserted the mag that was in the gun when this happened. It locked in fine but was a little more difficult to unlock. Then I looked at another mag, a Polish steel one and it had a large dent in it. Totally F'd. Follower is stuck, rounds just fell out after I took the first one out. 2 rounds also had dents.

    So im thinking out of battery fire and the bakelite mag didn't fly out due to resting on the ground. But none of the ammo got damaged either.

    Then I'm thinking maybe the pressure hit the metal mag causing it to have a huge dent but there's no damage or burn marks on the check rig where that mag was.

    Then I thought maybe the dent is unrelated and I simply fell on something when I went prone and didn't realize it in all the excitement. But I'm a lefty and that part of the mag was facing my body not the ground!


    WTF!


  5. #5
    Join Date
    Aug 2010
    Posts
    728
    Feedback Score
    12 (100%)
    Quote Originally Posted by Arik View Post

    Then I looked at another mag, a Polish steel one and it had a large dent in it. Totally F'd. Follower is stuck, rounds just fell out after I took the first one out. 2 rounds also had dents.

    Then I'm thinking maybe the pressure hit the metal mag causing it to have a huge dent but there's no damage or burn marks on the check rig where that mag was.

    Then I thought maybe the dent is unrelated and I simply fell on something when I went prone and didn't realize it in all the excitement. But I'm a lefty and that part of the mag was facing my body not the ground!


    WTF!

    I'm willing to bet that was the mag you used to smack the mag release then smack the cleaning rod while still at the range. Pressure from a stuck case did not dent that mag, and if you fell on something and did that while getting prone you'd remember. You used that mag like a hammer while in an excited frenzy to get back to the firing line and this is the result.
    “Twenty years from now you will be more disappointed by the things you didn’t do than by the ones you did do. So throw off the bowlines, sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.”
    - Mark Twain

  6. #6
    Join Date
    Jun 2015
    Location
    Georgia
    Posts
    3,104
    Feedback Score
    2 (100%)
    Quote Originally Posted by matemike View Post
    I'm willing to bet that was the mag you used to smack the mag release then smack the cleaning rod while still at the range. Pressure from a stuck case did not dent that mag, and if you fell on something and did that while getting prone you'd remember. You used that mag like a hammer while in an excited frenzy to get back to the firing line and this is the result.
    I was thinking the same.

  7. #7
    Join Date
    Jun 2015
    Location
    Georgia
    Posts
    3,104
    Feedback Score
    2 (100%)
    Start by squirting some Liquid Wrench around the casing and in down the barrel, and then give it an hour or two to soak. Then try removing the stuck casing again.
    “You have made us for yourself, O Lord, and our heart is restless until it rests in you.” -Augustine

  8. #8
    Join Date
    Sep 2015
    Posts
    444
    Feedback Score
    2 (100%)
    Quote Originally Posted by georgeib View Post
    Start by squirting some Liquid Wrench around the casing and in down the barrel, and then give it an hour or two to soak. Then try removing the stuck casing again.
    FWIW a DIY 50/50 mix of acetone and auto transmission fluid (ATF) was proven by Practical Machinist to be the BEST solvent for remove stuck or frozen items by a huge factor! 2X better than Kroil, which was the best of the commercially available solvents. LW was way down the list ...
    Given that 10-shots are a group and 5-shots may be a favorable trend ... know that just one good 3-shot group can make you an instant internet superstar!

  9. #9
    Join Date
    Aug 2015
    Location
    Midwest Flyover Country
    Posts
    3,742
    Feedback Score
    0
    delete
    Last edited by RetroRevolver77; 07-09-20 at 14:15.

  10. #10
    Join Date
    Dec 2011
    Location
    suburbs of Philly Pa
    Posts
    6,189
    Feedback Score
    1 (100%)
    Quote Originally Posted by RetroRevolver77 View Post
    Remove your muzzle brake. Run your cleaning rod down the bore until you make contact with the casing, then tap the rod with a hammer.
    Why didn't I think of that! I tapped the rod with a mag, the a hammer. When that didn't work I flipped it upside down and hit the rod against a concrete floor. Still stuck, but now at a gunsmith

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •