Primers popping out!!

Good evening all! Just got back from shooting my 7mm Rem Mag, ran out of my favorite load and it's no longer being produced, so I went with Hornady Superformance 139gr GMX. Well, I shot 12 rounds, and 3 of them lost their primers as they ejected, a few more have powder burns around the primer, and they broke my ejector... See pics for more details.

What is going on here? I did some work on my rifle over the last few days, but it was bedding it, so I assume it's not me, is the ammo faulty or too hot? Should I contact Hornady and see what they say?

http://photobucket.com/wtfrounds 2 more pics here

WTFroundsclose.jpg
 
That ammo is over pressure in your rifle. I wouldn't use that ammo any more or it will etch your bolt face.
 
Definately over pressure in your rifle. Stop shooting those immediately. I have a 7mm-08 that has heavy bolt lift when using the Hornady Superformance ammo.
 
I'm gonna go the other way.

If it was high pressure, the rear of the cases would have shown more pressure signs, you would notice it by the lettering on the rear of the case.

Too low of pressures would also cause the primers to come out, plus the smoking you have.

To see what I mean, load some pistol cases with just primers, no powder, no bullets. You'll see the primes will back out.

High pressure would cause the lettering to be smashed out of shape. Also the remaining primers don't look flattened out like what happens with high pressure.

This is just something to look at going only by your pictures.
 
I agree with Kraigwy, if this were a high pressure situation I would expect to see some glaring bolt wipe on the case head. It could be there and just not photographed well.

I'd call Hornady with the LOT Number and send them the pics. Because either low or high pressure is a bad thing for safety.

Jimro
 
Whether it is high or low pressure, it is like the guy who is hitting himself in the head with a hammer because it feels so darn good when he stops. Those rounds are not conventional ammunition. Buy some normal rounds and see what happens with them.
 
...3 of them lost their primers as they ejected, a few more have powder burns around the primer, and they broke my ejector...
This is not a low pressure problem, even if we don't see the usual ejector burnish/imprint marks. You also don't break/ruin ejectors w/ low pressure.

I suspect defective primer pockets and/or primers.
Get thee to Hornady ASAP with the pics and all other technical info you have.




ps: Measure the fired case length against that of the unfired case. See how much stretch you have
 
Looking at just the symptoms of a problem makes it really hard to find the cause. To me, it looks like the cases are too short or sized incorrectly. I doubt your chamber got longer. I'd measure the case lengths and post back. Someone can tell you if they are too short, but that is only one measurement of many that can be done without special tools. I'd contact Hornady and see what they say. If they say no problems, then I'd highly recommend taking the gun to a good gunsmith and have him measure the chamber.
 
I forgot to add, if you have some unfired rounds left, chamber them with 4 or 5 layers of paper in between bolt face and round. It shouldn't close or the bolt should be really hard to close. (don't force it closed or it might be really hard to open the bolt). It should allow only about 2 pieces of paper.
 
If there was excessive recoil when shooting these rounds then YES absolutely
those rounds were too hot. It looks to me like there is some cratering of the
primer as well. Another reason to consider reloading your own ammo. Don't shoot anymore of this stuff.
 
Superformance is known to be a hot load that is over pressured. Though as kraig and Jim said you would expect to see some wear on the rim of the case. Regardless i would switch ammo or get into reloading.

Bottom line hornady's superformance has had QC issues for quite some time now.
 
Those look like your rifle might have a "headspace" problem. If it's soly an ammo problem, Hornady cs is great to work with, I hope you find the problem and get it solved.
 
I sent the pictures to Hornady, we'll see what they say... The bolt was tough to lift on a couple rounds, I kept shooting due to stupid curiosity. I eyeballed the fired brass next to previously fired brass and unfired ammo from the same box, no micrometer available, but it doesn't look any longer or otherwise abnormal. I have shot many rounds of various types through the rifle without problems, I don't think anything could have changed as far as the rifle internals go. I'll post updates once I know more.
 
AMMO

I had the same thing happen with some Privi 308 ammo. Turns out just bad brass primer pocket where just a tad to large and after I shot them they over stretched and primers fell out. I bet you can push primers bad in with your finger without much trouble. Was glad to find out it was bad brass as I was going nuts trying to figure out what was up with my rifle. I got a couple of boxes of brass out the deal probably get the same deal from Hornady.
 
A friend of mine had that happen with his .270 with super-performance rounds. He only fired 5 out of the box and sent the rest back to Hornady. They told him there wasn't anything wrong with the ammo and sent him a full box.

I wouldn't shoot Hornady super-performance rounds in any rifle I have. It's not worth the risk...

Tony
 
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