View Full Version : Haha Oops.
Just had a customer come in with a DPMS SS bull barrel upper that the ejection port cover was not staying closed. Under further inspection i noticed that it had a bulged upper, a broken extractor and bolt catch. Also as i was switching out the uppers i noticed this.
http://i1067.photobucket.com/albums/u440/Jason_Prisbrey/20130430_123229_zps4cd25116.jpg
After i get the stuck casing out i will bore scope it and see if we can salvage anything.
Squib load maybe?
Dude, that's DPMS's latest high tech chamber coating. :D
Dude, that's DPMS's latest high tech chamber coating. :D
Haha that is freaking funny.
This stuck casing is being a bitch though. Anyone have any tips on how to get it out?
Dude, that's DPMS's latest high tech chamber coating. :D
Modular brass chamber lining - no mess clean up, just remove the stuck casing!
polymorpheous
04-30-13, 15:14
That's not a squib.
That's case head separation.
Was it a reload or 5.56 pressure round?
http://www.brownells.com/gunsmith-tools-supplies/handgun-tools/stuck-case-removers/broken-shell-extractor-prod23311.aspx
He was worried because his dust cover wouldn't lock shut? Looks like that was the least of his worries :D
That's not a squib.
That's case head separation.
Was it a reload or 5.56 pressure round?
http://www.brownells.com/gunsmith-tools-supplies/handgun-tools/stuck-case-removers/broken-shell-extractor-prod23311.aspx
He was worried because his dust cover wouldn't lock shut? Looks like that was the least of his worries :D
They were reloads of course.
It's a good thing he brought it in.
All I can say is wow, thats a lucky shooter that didn't have that gun blow up in his face.
All I can say is wow, thats a lucky shooter that didn't have that gun blow up in his face.
After talking with the owner more he was saying that when he fired the magazine ejected and the rifles didn't sound quite right (i wonder why)
He survived with no scratches at all.
bleaman225
04-30-13, 17:28
After talking with the owner more he was saying that when he fired the magazine ejected and the rifles didn't sound quite right (i wonder why)
He survived with no scratches at all.
Looks like natural selection doesn't get em all...
Anyone have any tips on how to get it out?
Try increasing larger cleaning brushes. Push past the neck from the chamber side, then pull back. The multiple wires usually will press against the case mouth and allow you to pull it gently out. Get the size right where the wires are almost straight is the trick. (IE: Not flexed, just bent rearwards)
Harder to explain than to do, it's amazing how well it works. Won't get every one, but worth a try as you probably already have brushes.
Since you're already doing the work, just get the case extractor. They're worth it.
texasgunhand
04-30-13, 22:39
Ouch, man he got lucky he didnt get hurt.
DIRTMAN556
04-30-13, 22:40
Whoa took me a second or two to see the stuck brass case. That's scary.
5.56 ruptured cartridge case extractor.
http://www.brownells.com/gunsmith-tools-supplies/handgun-tools/stuck-case-removers/broken-shell-extractor-prod23311.aspx
That's not a squib.
That's case head separation.
Was it a reload or 5.56 pressure round?What would cause a reload to have a case head separation like that? Too heavy a charge?
steyrman13
05-04-13, 15:49
What would cause a reload to have a case head separation like that? Too heavy a charge?
FL sizing too many times
FL sizing too many times
And overgassing can make it worse, as the case is yanked out while the brass is still under pressure and malleable. Stretches the brass a bit like excessive headspace would, just not as noticible.
You end up work hardening the brass. Its not always an excessive pressure thing.
Even with over gassing, the brass isn't under that much pressure when it's extracted
bluejackets92fs
05-04-13, 18:05
I've seen some shit but that takes talent.
What would cause a reload to have a case head separation like that? Too heavy a charge?
Yes. Too heavy of a Charge in all likelyhood... and considering the other damage to the gun that the OP mentioned.
Case separation isn't necessarily cause by this however. If the shoulder is bumped too far back when resizing. It'll cause permature case falure. I've had it happen like 3 times over the years. Not a big deal.
Yes. Too heavy of a Charge in all likelyhood... and considering the other damage to the gun that the OP mentioned.
Case separation isn't necessarily cause by this however. If the shoulder is bumped too far back when resizing. It'll cause permature case falure. I've had it happen like 3 times over the years. Not a big deal.
Wouldn't you have seen the "separation line" around/near the case head?
And how far back would bumping the shoulder too far be? I get some of my cases coming in just under the "min" step of a Dillon case gauge...most of them right at the step.
Wouldn't you have seen the "separation line" around/near the case head?
Sometimes. But at that point it's lucky it hasn't already let go. I've roasted a TON of .308 brass in my bolt gun by sizing it to the case guage instead of the chamber. :p Lesson learned.
For gas gun the gauge is the way to go.
And how far back would bumping the shoulder too far be? I get some of my cases coming in just under the "min" step of a Dillon case gauge...most of them right at the step.
I forget... Like .003"-.005" plus and you're damaging the case I think... There's a paper clip trick you can do to feel the case starting to separate on the inside, before you see it on the outside... but I've never been able to get that to work. :confused:
gunrunner505
05-06-13, 12:16
This stuck casing is being a bitch though. Anyone have any tips on how to get it out?
Did you get the case out? I might suggest an EZ Out like you would use to remove a broken bolt. That might give you what you need to twist it out maybe.
Sent from my SCH-I510 using Tapatalk 2
Sometimes. But at that point it's lucky it hasn't already let go. I've roasted a TON of .308 brass in my bolt gun by sizing it to the case guage instead of the chamber. :p Lesson learned.
For gas gun the gauge is the way to go.
I forget... Like .003"-.005" plus and you're damaging the case I think... There's a paper clip trick you can do to feel the case starting to separate on the inside, before you see it on the outside... but I've never been able to get that to work. :confused:
Gotcha. I know what you mean...and there's no way I'm over the .003-.005"...more like .001" as a rough guestimate.
Gotcha. I know what you mean...and there's no way I'm over the .003-.005"...more like .001" as a rough guestimate.
I don't know where I am either. For Bolt, I love it when you can just feel a little tension as you lower the bolt. Brass will last a LONG time when you get it just right.
Found a solution for DPMS parts
http://1.bp.blogspot.com/-KKQknHiX1ik/TeZL12cNTlI/AAAAAAAACbg/QWus7sHo0Hs/s1600/steel_trash_can.jpg
Did you get the case out? I might suggest an EZ Out like you would use to remove a broken bolt. That might give you what you need to twist it out maybe.
Sent from my SCH-I510 using Tapatalk 2
Yes we managed to get it out.
Even with over gassing, the brass isn't under that much pressure when it's extracted
In 20 inch rifle there is ~5,000 psi in the barrel when bullet is just about to exit. 14.5 inch has close to three times that!
Found a solution for DPMS parts
http://1.bp.blogspot.com/-KKQknHiX1ik/TeZL12cNTlI/AAAAAAAACbg/QWus7sHo0Hs/s1600/steel_trash_can.jpg
Wait a minute, it's not like any of the top names never had a stuck case. Lets be realistic about it.
Wait a minute, it's not like any of the top names never had a stuck case. Lets be realistic about it.
You're right, if you shoot garbage ammo in a Noveske you could have the same issue. But I wasn't talking about the OP's specific-problem-specifically ;)
In 20 inch rifle there is ~5,000 psi in the barrel when bullet is just about to exit. 14.5 inch has close to three times that!
That may be true, but that's not the pressure when the case is being extracted. The bullet has left the muzzle and the pressure in the system has begun blowing down before the carrier even begins moving.
Extraction from a self-loading rifle may add to case stretch (I have seen evidence that extraction can stretch cases in an M14) but the majority of stretch occurs at peak pressures when the case expands to seal the chamber
That may be true, but that's not the pressure when the case is being extracted. The bullet has left the muzzle and the pressure in the system has begun blowing down before the carrier even begins moving.
Extraction from a self-loading rifle may add to case stretch (I have seen evidence that extraction can stretch cases in an M14) but the majority of stretch occurs at peak pressures when the case expands to seal the chamber
It is a well understood potential issue in non-5.56 AR's. Severely overgassed guns will shorten brass life, see ripped rims, and increased case separations. All in a rifle/carbine that is properly headspaced.
Yanking the brass out early combines harsher extraction with softer/ malleable brass with higher "stiction" at the case mouth/shoulder.
Dirty/rough chambers compound the effect.
It should not happen in a properly setup AR. And may not have been the case here.
Just pointing out that before everyone leaps to the "excessive pressure" cause, there are often other causes.
I've stopped shooting commercial 5.56 reloads due to the risk of SAW brass.
The laws of physics apply even to the AR.
Yes, violent extraction shortens case life and that's what "over-gassed" ARs have. But the pressure has dropped tremendously before the carrier even begins to move because the bullet has exited the muzzle and pressure is venting through the muzzle before the case is extracted.
If extraction is stretching the case (and I have seen evidence it happens), it's not so much from the pressure, it's from being violently yanked out of the chamber from the momentum of the reciprocating mass. (Over-gassing causes higher BCG speeds and more importantly, quicker acceleration of the BCG.)
Brass fired in the SAW is bad because the headspace of SAW chambers are longer and the cases stretch, fire-forming to fill the extra space. When that happens, brass flows forward, thickening the necks and thinning at the web which, if not checked, eventually causes case head separation.
You don't want high pressure being released at the chamber end of your rifle. Believe me, it's unsafe for hundreds, let alone thousands of PSI to be released that way. It takes less than 100 PSI to destroy an eye or cause damage to skin. Autoloaders are designed to ensure extraction doesn't happen until gas pressure has dropped to safe levels.
I do agree with you that assuming this was due to excessive pressure is erroneous. If it were excessive pressure, the case would have failed differently
FL sizing too many timesHow many times would you say is too many times? I've read in various places that generally speaking 5.56 brass reloaded to 5.56 pressures can be reloaded 4 - 8 times max, depending on a host of factors.
I've reloaded pistol for a while, but I'm relatively new to reloading 5.56. Nothing beats visual inspections, of course, but it's helpful to have a reference point.
steyrman13
05-11-13, 15:04
How many times would you say is too many times? I've read in various places that generally speaking 5.56 brass reloaded to 5.56 pressures can be reloaded 4 - 8 times max, depending on a host of factors.
I've reloaded pistol for a while, but I'm relatively new to reloading 5.56. Nothing beats visual inspections, of course, but it's helpful to have a reference point.
I'm sure it all depends on the pressures, dies, etc. jstone or markm would be better at answering this than me. I'm newer to the reloading crowd too
It all depends. If you don't overwork the brass by bumping the shoulder back too far, or load it really hot, 4-8 is very doable.
Brass with either break/separate, split at the caseneck, or the primer pocket will get too loose.
I've been playing with the small font headstamped PMC (not PMC Bronze) and PMP brass. And that stuff is sturdy. Thick old case webs. You have to download by a full grain because the case capacity is less... but the primer pockets stay really tight.
I've even been annealing the necks to see just how long they'll last.
Since this has turned into a reloading thread, I guess I'll ask this here instead of making my own thread...
I use the Dillon SS to swage my crimped pockets on LC or other brass. How do you guys mark your brass so that you don't pick it up and re-swage the same primer pocket, thus loosening it up too much? Some primer pockets are easier to see if there's a crimp than others, so what's another method besides visual?
If I get a bunch mixed in, I'll sort them apart before doing anything with it. If I can't tell, I toss it in with the brass that has the crimp removed. Then if it won't take a primer, I deal with the crimp at that point.
I'm hand priming though... I keep my hornady crimp removal bit in the drill all the time and just zap cases as needed.
Those must have been one of his experimental loads. One of those, "hey look, I can make this thing shoot really far!"
Trigger pull...hey, that didn't sound right. :confused:
Averageman
05-18-13, 10:06
So there than the broken shell extractor what did you use?
I've had good luck putting metal parts in the freezer when I've had issues.
I have a 16" DPMS SS Bull Barrel. My barrel is marked .223 NOT 5.56. I mention this because I have double checked my chamber with Ned's gauge from Michiguns. It is truly a .223 chamber. I also have Ned's reamer but have purposely kept this chamber .223 instead of "fixing" it. Just be careful not to put 5.56 ammo in it. Perhaps this is what might have happened?
Ouroborous
05-19-13, 14:12
Sometimes. But at that point it's lucky it hasn't already let go. I've roasted a TON of .308 brass in my bolt gun by sizing it to the case guage instead of the chamber. :p Lesson learned.
For gas gun the gauge is the way to go.
I forget... Like .003"-.005" plus and you're damaging the case I think... There's a paper clip trick you can do to feel the case starting to separate on the inside, before you see it on the outside... but I've never been able to get that to work. :confused:
Markm, I was under the impression that when your cases start being hard to chamber in an AR, bumping the should back .003"-.005" was the correct amount to bump for reliable chambering. From what I hear, this doesn't need to be done till the 4th or 5th loading.
Does this sound correct?
I have an RCBS 223 case gauge. I shoot a box of factory m193 or 885 through the rifle and measure the cases. For example my main rifle is +.004. When I reload for that rifle I set up the FL sizer for +.002 and bump the shoulder back .001-2 based on how many firings on the brass. As the case work hardens, I find the bump gets less about the fourth reload. If you get erratic bump back on new brass use more lube.
On 4-5 reloads I only bump the shoulder back a total of .008 -.010 instead of .020 which saves alittle on trimming and I generally load 24.5 of TAC with a 55 for blasting ammo so I generally only have to trim once after initial sizing for 4 reloads.
ETA:
My SCAR has a 7.62 x 51 chamber whi h is reportedly .005 longer to the shoulder than a 308 Win which sounds about right since cases come out on a 308 gauge @ +.007. I FL size them to +.005.
Factory new brass for 223 and 308 generally run SAAMI -.004 so my scar brass is growing .011 the first firing. Food for thought.
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