AR overpressure case rpture!!!

[billy_56081]

I was out with my friend today and had a case rupture. The magazine blew out of the gun, it swelled the magazine and blew the remaing rounds spring and follower.




What we came up wit was I had fired a round before this, it apeared that we had a failure to eject. I pulled back the bolt handle ejected an empty case and returned the rifle to battery. One the next shot is when we had the blowout. We started examining the ammo that my friend had reloaded for his rifle. The bullets were not seated very deeply. And could be pulled with our finger. What we decided was the prior round was not and empty round but a misfire. The case came our without the bullet. When the next round was fired we had 2 bullets. I must say his AR handled the pressure very well by venting it out the magazine. I am glad no one was hurt. We had to tap the case out with a hammer and rod. Only damgae was the extractor and his pride.





Lesson learned seat bullets deep enough to have good purchase and I advised his to get a Lee factory crimp die. 

[Arier Blut]

http://www.youtube.com/watch?v=tWygoxV_ApM

Warning video of AR blowing out magazine has cussing!

I bet he puckered up a bit.
Glad to hear that neither of you were hurt. I run the lee factory crimp and set it to crimp a whole lot more than it should. As you said lesson learned. I hope he get's a new appreciation for reloading so there will be no more chance for injury.

[billy_56081]

I am glad to report that the rifle when fired today gave a satifactort 10 shot ragged one hole group of .75. It is a colt factory match.

[teddy12b]

Did you have a gunsmith look over that rifle just to make sure it's safe?  Colt or not, I'd really consider having a qualified gunsmith look that rifle over before shooting it again.  A stitch in time saves nine....

[CannonKrazy]

http://www.youtube.com/watch?v=tWygoxV_ApM

Warning video of AR blowing out magazine has cussing!

I bet he puckered up a bit.

Nope you are wrong. He didn't have time to pucker. The only thing left for him to do now is go change his underware and wash his stinking azz.

[billy_56081]

That is the same thing that happened to us. It didn't so much scare us as it was juzt wonderment to see the magazine blow apart out the bottom. I was standing and shot it from  the hip to get rid of a couple rounds.

[Lloyd Smale]

its a testimate to how tough and well designed an ar really is. Id check your bolt over good for cracks and if it looks good the rifle is probably fine.

[Graybeard]

This WAS NOT a case of OVER PRESSURE but rather a barrel obstruction.

[billy_56081]

I guess yeah and no on the barrel obstruction. It was as much firing a 100 grain bullet out of a .223 case with the correct powder charge for a 50 grain bullet. Luckily the bullets were tight together with no airspace between them or we might have bulged the barrel. If I can get the group picture from my phone uploaded we can see luckily no damage done.

[Graybeard]

You can't be serious.  You admit to their being a bullet in the barrel somewhere but there is no way you knew where since you jammed another round in behind it that means it was at least far enough down the barrel for another to chamber. Then you fired with a projectile in the barrel another round and say that's not a case of a barrel obstruction? I suggest you look up the definition of the word then.

[billy_56081]

Bill, the bulet would have only reached the lands at most, my friends reload were very loose. The bullet in the second round could be seated deeper in the case by finger pressure.





Pic after removal of stuck case. 10 rounds 100 yards called flyer.




Pic of ruptured case.

[LEO]

I am glad that no one was hurt, in the mishap.  Based on the information that you provided about your friends reloads it sounds like he needs to break those loads down and start over perhaps after reviewing instructional materials on how to reload for a semi-automatic firearm.  Rounds with the bullet that loose are fine for single shots but are a disaster waiting to happen with a semi-auto, if the bullet is pushed deeper into the case upon feeding it can cause a dramatic increase in pressure for an otherwise safe load.  I know there are those that believe a tight neck or crimp cause a decrease in the accuracy of a load but even if that is true, it is not worth taking the risk to gain a small decrease in group size.  Once again I am glad no one was hurt.

[billy_56081]

All the remaining loads were disassembled.

[Dee]

billy, GB is right. A bullet in the barrel at ANY point, whether at the chamber mouth, or halfway down the barrel, if in front of another loaded round is a barrel obstruction, which CAUSED excess chamber pressure. It is good that no permanent damage was done to you or the rifle. I would also pay close attention to the cluster on the bolt to make sure none were damage when it was forced open.

[billy_56081]

Thanks Dee, our friend that got it open is a licenced gunsmith he inspeted and gave us the ok. Ole Jarad will definitly pay more attention to his handloading tecnique from now on. I have to wonder if we shouyld mic. the bullets. We have loaded others where they had only about .1 ionch holding in the neck and they sure held better. The bullets used were remington 50 powerloct hollowpoints. Whether folks like them or not he has invested in a LEE factory crimp die for his auto reloads.

[Lloyd Smale]

i dont think a factory crimp die is going to do squat for you. Ive fired 100s of thousands of .223s out of ars and never used a crimp die. My guess is either you had a very weak primer or more then likely you had a case that didnt get a powder charge. If it had powder in it you would have had powder spilled all over the gun when you ejected it. more the likely the primer popped and sometimes you cant even here them pop and that force was enough to push the bullet into the rifling. If you have bullets that are loose in the case neck you have one of three problems. either your dies arent sizing the neck down enough, your expander is to big or your seating your bullets so deap that your into the oglive of the bullet. A factory crimp die is a pour bandaid for any of these problems.

[billy_56081]

Lioyd, after observing everything. We found 1. we had a case on the ground with no primer strike. 2. there was powder in the gun . 3. we could either push or pull the bullets by finger pressure. 4. the only bullets we could do this with was the Remington power loct. 5. A Lee factory crimp die or  good roll crimp would have stopped this from hapening.