Bulged Barrel?

Discussion in 'Technical Questions & Information' started by ryan42, Sep 25, 2012.

  1. 76Highboy

    76Highboy Well-Known Member Supporting Member

    Joined:
    Jan 1, 2012
    Messages:
    8,702
    It is all in perspective. I just had a revolver where I stuck 3 bullets into the barrel with no damage and had to drill them out, and then I have seen shotguns explode due to mud in the barrel. Then, I have read where barrels have been damaged due to over oiling and then trying to fire them. It would be nice to know what caused the barrel to bulge.
  2. JLA

    JLA Well-Known Member

    Joined:
    Feb 26, 2007
    Messages:
    18,261
    Location:
    Heart Of Texas
    Yep too many variables. Hes shooting .45 ACP so pressure isnt likely a cause. Due to the low pressure and low velocity of the .45 ACP that all but rules out partial obstruction like too much oil. In my mind the only real possibility here is a stuck bullet.. Perhaps a bridged powder dump from the measure and the round that stuck only got a half grain of titegroup or so. Which means there could be a round in the rest of the loaded ammo with a near double charge.. :eek: Or best case scenario.. A round simply didnt get charged with powder and the primer just pushed the bullet an inch or so down the barrel where the next round fired normally collided with the stuck bullet and both went on to the target..
    Last edited: Sep 26, 2012
  3. ryan42

    ryan42 New Member

    Joined:
    Jan 28, 2012
    Messages:
    1,665
    Location:
    marion indiana
    Im sure your right.:)
  4. CCHolderinMaine

    CCHolderinMaine Well-Known Member

    Joined:
    Mar 21, 2012
    Messages:
    1,850
    Location:
    Steep Falls, Maine
    Care to throw a number at the % of the time a bullet stuck in the barrel will be "pushed" out by the next round verses exploding barrel syndrome?
  5. 76Highboy

    76Highboy Well-Known Member Supporting Member

    Joined:
    Jan 1, 2012
    Messages:
    8,702
    Your analysis is kind of why I think that someone stuck two bullets in the barrel and caused the barrel to bulge and got rid of it. Then Ryan gets the gun and the continued use causes the barrel to begin distorting just enough to cause the slide to jam against it. That is what comes to mind with me. Past that, I am clueless. As far as one bullet knocking the first one out I am not sure about that and have never heard of it happening.
  6. Jim K

    Jim K New Member

    Joined:
    Dec 6, 2009
    Messages:
    6,397
    The actual cause of a bulged barrel is often misunderstood. It is heat. When the bullet begins to move, it rapidly picks up a lot of kinetic energy. When the bullet is stopped abruptly, that energy is dumped in the form of heat. That heat softens the steel of the barrel and the normal pressure bulges or breaks the softened steel.

    If the bullet is not stopped, or slows to a stop, the energy dump is not as abrupt and the heat has a chance to dissipate. That is the case with a soft material in the barrel (peanut butter?) or with something like rainwater, which does not slow the bullet significantly. But if the front bullet is at the rear, so the second bullet is touching it, the second will not be stopped, and the two bullets will exit as one, at effectively double the mass. The pressure will be higher than normal, but the the barrel will not bulge.

    Also, if a bullet is stuck in the barrel and a round without a bullet is fired, the powder gas alone does not have enough kinetic energy and is not stopped abruptly enough to cause a bulge. In fact (dirty little gunsmith secret) a common way of removing barrel obstructions like broken bore snakes is to use a half charge of powder without a bullet and simply shoot them out.

    Jim
  7. dcriner

    dcriner Member

    Joined:
    Apr 18, 2011
    Messages:
    367
    Location:
    Illinois
    Jim, I'm trying to reconcile that versus a muzzleloader with the ball not rammed tight against the powder charge, leaving a vacant space behind the ball. Supposedly, that will increase the pressure and somehow damage the bbl.
  8. CCHolderinMaine

    CCHolderinMaine Well-Known Member

    Joined:
    Mar 21, 2012
    Messages:
    1,850
    Location:
    Steep Falls, Maine
    Also, if a bullet is stuck in the barrel and a round without a bullet is fired, the powder gas alone does not have enough kinetic energy and is not stopped abruptly enough to cause a bulge. In fact (dirty little gunsmith secret) a common way of removing barrel obstructions like broken bore snakes is to use a half charge of powder without a bullet and simply shoot them out.

    Thank you for that answer, that's a question I've wondered. So what you're saying is; even if I cemented shut the end of a barrel with something completely immovable, even if I fired a full normal powder charge(no projectile), the barrel should not be damaged.
  9. jaydub

    jaydub Former Guest

    Joined:
    Apr 7, 2012
    Messages:
    43
    All my Glocks have after market barrels. I highly recommend this as the way to go.
  10. Jim K

    Jim K New Member

    Joined:
    Dec 6, 2009
    Messages:
    6,397
    Hi, dcriner. I have heard that time and again, but I tried it and nothing happened except the bullet blew out. I have even challenged one fellow to prove to me that it can happen and offered to pay for the rifle if the barrel burst or bulged. He refused, but kept insisting that he read that someone said that maybe it happened to a cousin.... You get the picture.

    Hi, CC holder. Well I have never tried cementing the barrel shut, but I think the answer would be that with no bullet the plug would just be blown out. Now if a bullet were fired, the precursor wave would probably blow out the plug. But if it didn't, and the bullet stopped, the muzzle would be opened up the same as when a rifle is fired with mud in the barrel. Those kinds of obstructions usually result in the barrel splitting along the fault lines (that is the rifling) and the barrel opens up in a nice flower pattern.

    Of course, you made your plug immovable. What would happen is just that the pressure would build up as the powder burned. If the barrel were weak, it could burst, but with a normal barrel that gas would be contained. The pressure would be lower than normal chamber pressure since the gas would have much more room for expansion than in just the chamber.

    Jim
    Last edited: Sep 27, 2012
  11. targetacqmgt

    targetacqmgt New Member

    Joined:
    Sep 21, 2012
    Messages:
    494
    Umm what kind of oil-thick viscosity? I know about using a liight coat of oil-but never heard of oil as obstruction. Cosmoline yes:eek:
  12. CCHolderinMaine

    CCHolderinMaine Well-Known Member

    Joined:
    Mar 21, 2012
    Messages:
    1,850
    Location:
    Steep Falls, Maine
    I guess you've finally helped me boil my question down. Is the barrel capable of withstanding the same pressures as the chamber is? Is the chamber stronger in any way that the barrel?
  13. ryan42

    ryan42 New Member

    Joined:
    Jan 28, 2012
    Messages:
    1,665
    Location:
    marion indiana
    Now that you said that im going to take the rest of the bullets apart to make sure there is no double charge thanks for mentioning it.Know matter how much one thinks he knows about guns its amazing how much we dont know.:)
  14. dcriner

    dcriner Member

    Joined:
    Apr 18, 2011
    Messages:
    367
    Location:
    Illinois
    If a little extra Rem Oil swabbed in the bore can cause a barrel to bulge, or worse, think about a muzzleloading musket rifle loaded with a Minie ball, gooped up with grease in its grooves and base.
  15. JLA

    JLA Well-Known Member

    Joined:
    Feb 26, 2007
    Messages:
    18,261
    Location:
    Heart Of Texas
    Excess Oil CAN cause barrel damage. Thats why it says in the owners manual for your firearms to not leave excessive lubricant in the bore if you are going to shoot it. Obviously thinner, less viscous oils wont pose as much of a threat as they are more likely to just get pushed out ahead of the bullet. but it can happen ere regardless.
Similar Threads
Forum Title Date
Technical Questions & Information Bulgeded Barrel on a Winchester Oct 14, 2009
Technical Questions & Information Dan Wesson barrel removal? Nov 18, 2014
Technical Questions & Information Rifle scope height above barrel Nov 15, 2014
Technical Questions & Information What is the approx. cost of changing barrels and cal. Nov 5, 2014
Technical Questions & Information Does Linseed Oil form a polymer layer when baked on a barrel? Oct 28, 2014

Share This Page