Primer Problems

[dhutch]

So I took the new LR 308 to the range today. Picked it up a few weeks ago. Has a 24" Bull Barrel and JP Enterprise adjustable gas block.

I had 2 boxes of Hornady's new Super Performance 150gr SST rounds. Didn't know much about the round but I figured since it was a birthday present I'd use it to get the new rifle on paper.

Here's where the problem is......the first 5-10 rounds had punctured primers or severely deformed primers, after being fired. I thought maybe it was the firing pin being too long since it was puncturing a perfect hole and showed no signs of the primer flattening. Happened to have a spare parts kit for the bolt setup and replaced the firing pin with a new one, and the same happened. I gave up on the ammo at this point and switched to my reloads. 155gr SMK Palma, CCI Large Rifle Primer, and 45.5gr RL15. The problem went away........

Bad lot of ammo? or Over pressure for this particular factory load?

Two Hornady Factory rounds on left and Reload on right.

Oh and are these marks on the neck normal for a gas gun?

 

[Falar]

Re: Primer Problems

Just a guess, but that ammo may be too hot for "some" semiautos. Hornady has always advised against using their "Light Magnum" .308 loads in gas guns, maybe you should inquire if the same is true for the Super Performance ammo.

I've hotrodded pretty hot in my gas guns, never pierced any primers.

 

[dhutch]

Re: Primer Problems

It looks like Hornady compares them to Light Magnum loads.....maybe we'll just not shoot these in the gas gun....

 

[SNAFU_]

Re: Primer Problems

I would call Hornady directly and see what they say. If there is no warning on the box, I am sure they would be interested in hearing about this....you might even get some replacement ammo out of them.
1-800-338-3320

 

[vmpglenn]

Re: Primer Problems

Hornady advertises the Superformance line to be safe in all guns, including semiautos.

I have not had any pressure problems in my KAC SR25 EMC, SR25 EMR or LaRue OBR. It's been my experience that DPMS chambers are cut VERY tight to help accuracy.

 

[Grump]

Re: Primer Problems

The case neck marks are fairly normal. I've even seen a bolt gun put an occasional scratch on the neck. The other one could be a random ding from ejection.

Looks to me more likely to be a bad batch of primers than totally bad or overpressure ammo. I put a LOT of stock in velocity vs. barrel length vs. published data as an indirect indicator of pressure. Your rifle and ammo show no *other* discernable pressure "signs", so I suggest you mail two leaky primer fired cases and two normal-appearing ones back to Hornady. Call first so you can address it to the right department/person. That's the good and Christian thing to do, so their QC people can look for any problems and correct them. Makes da world a better place, don'chaknow?

Now, if you do have chronograph figures and were delighted to see that the ammo shoots even faster than Horndady says it should from your barrel length, then it's probably either too-hot ammo or your chamber/bore combo is a high pressure rig that needs special handling to include not using that stuff any more.

 

[Unknown]

Re: Primer Problems

If you hadn't fired your reloads without a problem, I would suggest that perhaps DPMS short throated your rifle as they did mine.

However, because your loads work fine, that isn't the issue. Although DPMS eventually fixed my short throat, they never admitted to doing so...but that is another thread.

 

[LimaBravo]

Re: Primer Problems

Have you tried the Federal TRU ammo?It's made specifically for semi autos.