Ruptured case - Black Hills .223

[WalkerTexasRanger]

I had my first ruptured case today, Black Hills Blue Box .223 68 grain moly.

Case tore right in half about midway up from the base. What the heck causes this?? Poor brass, rifle problem, any ideas??

Also, after the case blew, intermittent rounds showed a ring in the fired brass in a similar spot to where the case tore apart. Could the case rupture have damaged the chamber? And if so, wouldnt all the cases have show the ring. There is no buldge, just a discoloration ring.

Any thoughts would be greatly appreciated!!

WTR

 

[Coltdriver]

What kind of gun were you shooting out of??

 

[WalkerTexasRanger]

It was a Rem 700 VS...

 

[hps1]

Case tore right in half about midway up from the base. What the heck causes this??

Usually, case separation is caused by either too many reloadings on a particular piece of brass or by over-sizing (over working) your brass. Reloading for gas guns requires care to size sufficiently for the tightest chamber to avoid slamfires and commercial reloaders, I would suspect, may size a bit more than most shooters reloading for one particular rifle in order to give them some measure of safety margin. The shooter who reloads for one rifle can use a cartridge case gauge to measure a once fired case from his rifle, then set his dies to form the case just a few thousandths under that measurement, thereby working the brass a minimum amount to avoid case separation.

I am not all that familiar w/223 reloading, but with GI brass in 30-06 or 7.62 Nato, it is common to find brass that has been fired in machineguns with rather sloppy chambers, resulting in more stretching of the brass in this area (the head/web area). Don't know if the full auto 223's have somewhat sloppy chambers as was common w/the larger MG's, but would suspect that would be the case.

Your description of "about midway up from the base" seems a bit unusual to me, however, as work hardened or over-worked brass usually separates right at the web of the case, that is to say, where the case wall joins the head of the case.

Many service rifle shooters feel the need to use small base dies to bring the cases down considerably in size. This causes work hardening of the brass and expedites case failure. Perhaps this is necessary in some rifles; personally, I have never had a problem sizing brass to fit any of my (30-06 or 308) rifles using standard dies.

Just before case failure occurs, it is common for a bright ring to appear at the web of the case. I suspect that is the ring you are seeing on some of your fired cases. You can bend a paper clip 90* and use the hook to "feel" the inside wall of the case for a groove at the web which serves as a warning that the case is about to fail and should be discarded.

Black Hills has a very good reputation in the competitve shooting circles and I would suspect that they attempt to use only once fired brass, but don't know where they obtain their brass or if there is a possibility that it could have been used in full auto weapons or not.

Were the cases military headstamp?

Regards,
hps

 

[JohnKSa]

Is it possible that the rifle could have a headspace problem? (Amateur rebarrel/rechamber, etc.)

 

[WalkerTexasRanger]

It was Lake City cases, and Blue Box means once previously loaded. So, should have been only its second load.

I do reload, and if it had been one of mine, would have thought as you wrote, too many reloads, but since it was BH...

I have had great success with the BH to this point, and continued to shoot the rilfe after getting the two pieces of the case out. It was separated halfway between the base and the shoulder, right in the middle of the case. Bizzarr, I know.

The rifle is basically new, straight from Rem, less than 200 rounds down the pipe. No modifications at all.

Again, my main concern is damage to the chamber, or if this is even possible? I will just throw out the remainder of that box of ammo and will move on to another.

I have shot this same ammo in my AR, my LTR, and my Win Mod 70, just thought I would see how it did the VS.

Thanks for the suggestions, and keep them coming!!

WTR

 

[rbernie]

If there was damage to the chamber, I'd guess that you should be able to see it. If you've examined the chamber and seen nothing but a nice shiny smooth uninterrupted surface, I'd either shoot a different ammo and see what happens or (if you really feel like something may be wrong with the rifle) have the headspace checked. Since 223 is a common chambering, you'll likely find several local gunsmiths/shops that can do this for you for low/no cost.

Were I you, I'd probably just shoot another brand of ammo before I ran off to have the headspace checked. But I'm not the brightest bulb in the box sometimes, either.

 

[DnPRK]

Check your ammo in a case length gage. I bet it is too short.

Chances are that the case shoulder was pushed back too far during sizing. This creates the same effect as excessive headspace. During firing, the case sides expand to grip the chamber, the case head then gets pushed back (stretched) until it contacts the bolt face. Excessive stretching causes a shiny ring ahead of the case head, or at worst, causes case head seperation.

 

[Samuel_Hoggson]

First, cease fire!!!!

To check the unfired rounds for headspace issues will require something other than a case length gauge. Something like the RCBS Precision-mic would do it.

I'd check the chamber too. I don't remember if headspace (go, no-go, field) dies can be rented from Brownells, but it's worth a look.

I would not shoot the gun with different ammo until I'd made sure that the BH stuff was the cause of the problem. It is entirely possible that your 700's chamber is out of spec. I assume you understand the difference between 5.56 and .223 chamber specs, and that you also understand the ramifications of these differences vis-a-vis ammo selection. If not visit the ammo-oracle on arfcom.

You have not likely harmed the gun to this point.

BTW, what you are describing sounds very, very, very much like what would obtain if you fired .223 in a .222 Mag chamber............????

Sam

 

[WalkerTexasRanger]

The BH ammo is supposed to be .223, not 5.56. Yep, do understand the difference.

I have fired other BH ammo in the gun with no problems, and also some of my handloads.

I do have a stoney point headspace gauge, and guess I could pull a bullet and check the brass that way.

Just measuring the fired brass, overall lenght is 1.765, slightly long IIRC. 1.760 should be max, trimmed to 1.750.

 

[WalkerTexasRanger]

Checked the ammo with my Stoney Point gague, tell me what you think. All my handloads and the all the other BH ammo I have measures 1.463-1.461.

These three boxes of 68 measure 1.455. Significantly shorter. DnPRK's analysis sounds correct.

IIRC correctly, my fired brass measures about 1.465 -1.464 and I am trying to bump the shoulder back .002-.003. This shoulder is bumped WAY back to 1.455, therby creating the excessive headspace and the separation.

Anybody interested in 3 boxes of BH 68??????

 

[Samuel_Hoggson]

Well, BH sure as heck ought to be interested in those 3 boxes. I'd contact them and see what they're willing to do.

Sam

 

[Steve Smith]

HEY! READ THIS!

BH put out some ammo last year that was too hot and the Marine Hghpower team stopped using it after case ruptures at Quantico. It is possible that it also has been sized too short. You MAY have some of it...call them and ask them about lot numbers.

I wonder if you'll read this.

 

[WalkerTexasRanger]

Steve - Thanks

Will call BH, but there is not lot # on the boxes..

 

[WalkerTexasRanger]

Called BH today, they told me where to find the lot #, which I did, and he told me that he would "look into it" and will call me back.

I told him that it is obvioulsy short, and ask what I should do with the ammo, he basically told me to throw it away. 3 boxes, bout $18/box, just throw it away?? No offer of anything from his part. I guess that I could have reloaded it and be trying to pass off my handloads back on them. Or, I guess they could pull a bullet and check the powder and charge and confirm it is what they use.

Whatever, just sort of goes against me to throw $54 in the trash...

I guess I could at least pull the bullets. I dont know any way, once the shoulder has been bumped too far back, to get it back out.