LR-308 build and an ammo issue\warning

quantumkid

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Minuteman
May 10, 2012
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Glen Burnie, Maryland
I got a new job and decided to celebrate by building a 308 AR variant. Here are the specs of my build:

Started with a DPMS LR-308B
Installed Geissele SSA trigger
Magpul PRS stock
BCM Gunfighter large charge handle
ERGO Sure grip
Spikes Heavy buffer and spring
PRI Adjustable gas block
YHM mount risers
Burris Xtreme Tack mounts
Busnhnell Elite Tactical 6-24X 50MM - G2DMR mildot scope
Buttler creek caps
Harris bipod
Barrel threaded by YHM

Hscdv.jpg


On to the ammo issue:
I've fired about 140 rounds through the rifle. Three of the boxes were pain old federal I cycled through for breakin and unfortunately I gave my brass away to a guy who was at the range looking for brass to reload. So the next time out I shot a box of Hornady Superperformance which ran fine with just a bit of signs of timing issues but I expected that on a carbine length system. In preparation for an upcoming fun shoot I went looking for some good ammo. I decided I would try the Hornady A-Max match 168 Grain, but was unable to find any. Then I found out via several posts and a quick call to Hornady that the Z-Max ammo is suppose to be the same only with a green tip. The BC and muzzle velocity on the box are identical. So I bought 5 boxes and took one to the range to zero in. I got about 17 rounds in when one shot produced a lot of gas so I stopped and check the rifle and find my brass. I only found 14, but they had a lot of cratering and heavy swipes. I finished the last three and again had a punched primer this time confirmed by the spent cartridge. Thinking I was still having a timing issue or headspace problem; I bought the spikes heavy buffer and PRI adjustable gas block. I checked the headspace with go no-go gauges and it checked fine. Finally today I went to the range again with the parts installed. I shut off the gas completely and fired three rounds of the Z-MAX again I got heavy swipes on two and a punched primer on one. Then I turned the gas back up so the gun would cycle and ran through 10 rounds of federal power shock soft point and they all came out fine. I did a bit of searching when I got home and found a review of the Z-Max where the reviewer had a primmer pop on him as well ( Z-Max Review ). I've contacted Hornady and am sending the ammo to them, but I thought I would post this here just incase anyone else has had the same issue or runs into the same issue with this ammo. Hopefully this is just a bad batch, but a few other reviews and posts I read today make me think it may be an issue in general. Below are some pictures of the brass.
Top is super performance
Middle is Z-Max
Bottom is Federal power shock soft point.

5NCqa.jpg
BrJZz.jpg



Now i need to find some good match ammo to use for my first fun match on the 27th.
 
Re: LR-308 build and an ammo issue\warning

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: insight3b</div><div class="ubbcode-body">Hopefully Hornady will recall this lot of Z-max before someone gets hurt...glad you're ok </div></div>


They won't, I'd put money on it. This has been an ongoing issue with their Superformance and Custom ammo line in AR platform rifles for a while now. The ZMax ammo is nothing more than re-branded Superformance.

I sent them 3 boxes of 6.8SPC ammo that was way overpressure in the 3 rifles I tried them in. I was told that the ammo was tested and showed to be "in spec, but we will replace it for you at no cost". 5 rounds from the new lot, same problems (blown primers, heavy extractor marks). Sent THAT back to them again, same answer along with "are you sure this isn't an issue with the gun?" Funny, it ran SSA Tac loads like a champ and the brass was fine. Most of my handloads were well above max before encountering pressure signs as well.

A good friend of mine lost a bolt carrier assembly and a barrel to a box of their 6.5 Grendel ammo. Case head seperated, pressures were high enough that you could read part of the headstamp from the brass in the bolt face.
 
Re: LR-308 build and an ammo issue\warning

I had blown primers in the 7m008 AR that I had, it was Hornady Superperformance ammo.

However I did not see the same in the 6.5 Grendel Hornady ammo (123gr Amax) and I do not believe that is Superperformance recipe.

BB