PWS MK214 and some blown primers

[venharis]

I went to the range yesterday and took along some 168 gr match partizan ammo and guess what happened..

. I had previously tried two other types of ammo before this and had no problems.

I got home and cleaned the rifle out and everything looks ok. There appears to be some signs of over pressure on the brass as well, What do you guys think... bad primers of too much powder?

I only bought three boxes as I always try new ammo before making a big commitment.

I installed a new CMC trigger group and it makes the original feel like dragging a sled over rocks.

Fit and finish is pretty good actually. This trigger group is for an AR-15 but it seems to work on the PWS MK214. Any thoughts on this Could this be the source of the trouble?... I seriously doubt it but hey you never know...

I put a bushnell 3200 on a PEPR mount. I figured I need to learn range finding with mildots.
The Magazine is an AR-Stoner Magazine DPMS LR-308, SR-25 .308 Winchester 20-Round with Anti Tilt Follower Stainless Steel Black for 18 bucks. It seems to work better than the Magpul as I did not experience any failure to feed. I think it looks better as well.

BTW I went out on a limb with this tipton gun vise and it works like a champ, I would buy it again... John

 

[DMack]

Re: PWS MK214 and some blown primers

I shot two boxes of Privi in my PWS MK214. I had two blown primers with the 168 grain but none with 175 grain. I said it was bad ammo.

No issues out of any other ammo.

As for the trigger, that wouldn't be your problem. I run a Geissle SD-E in mine

How many rounds through it yet?

 

[2ndPanzer]

Re: PWS MK214 and some blown primers

The PPU 168 Match has blown up 2 308 AR's recently, an OBR and I believe a DPMS. Apparently it is a bad lot that came through. I wouldn't shoot the 168 PPU through any of my rifles, Just too much risk recently with the ammo, but I have never heard of issues with the 175 load. The 168 load however has had more than a few reports of the exact issues or worse than yours. Not worth the risk to me. Of course there have been thousands of 168 PPU rounds fired with no issues, for years, and they will be along shortly to say the ammo is fine, and your gun is broke, but if you search around here, arfcom, google, etc. you will find several reports recently, within the last 6-8 ,onths, so I am guessing a bad lot got out.

 

[venharis]

Re: PWS MK214 and some blown primers

I have about 100 rounds through it, Accuracy is not great but I suspect the PEPR mount was not installed tight enough. I will run some Federal Premium Gold Medal Ammunition 308 and adjust the mount. I ought to run a patch with some sweets just to see if copper fouling is an issue, I doubt it but just a sanity check...

 

[DMack]

Re: PWS MK214 and some blown primers

You will find that your MK214 is VERY accurate... As long as you run it properly. I've written on it extensively and addressed most of the concerns in that thread. I have about 1100 rounds through mine, and it continues to amaze me. The rifle is way better than I am.

 

[venharis]

Re: PWS MK214 and some blown primers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Venharis</div><div class="ubbcode-body">I went to the range yesterday and took along some 168 gr match partizan ammo and guess what happened..

. I had previously tried two other types of ammo before this and had no problems.

I got home and cleaned the rifle out and everything looks ok. There appears to be some signs of over pressure on the brass as well, What do you guys think... bad primers of too much powder?

I only bought three boxes as I always try new ammo before making a big commitment.

I installed a new CMC trigger group and it makes the original feel like dragging a sled over rocks.

Fit and finish is pretty good actually. This trigger group is for an AR-15 but it seems to work on the PWS MK214. Any thoughts on this Could this be the source of the trouble?... I seriously doubt it but hey you never know...

I put a bushnell 3200 on a PEPR mount. I figured I need to learn range finding with mildots.
The Magazine is an AR-Stoner Magazine DPMS LR-308, SR-25 .308 Winchester 20-Round with Anti Tilt Follower Stainless Steel Black for 18 bucks. It seems to work better than the Magpul as I did not experience any failure to feed. I think it looks better as well.

BTW I went out on a limb with this tipton gun vise and it works like a champ, I would buy it again... John

</div></div>

OK somewhat of an update... I figured that the reason for the blown primers is the much lighter hammer on the CMC trigger group. I think that the firing pin is being pushed back into the bolt prematurily during cartridge ignition. As evidence I first will see little brass tits on the primers for a few rounds before the primers actually start to blow. I will clean up the firing pin tip and replace the CMC trigger with the original and fire a few boxes of ammo and gat back to this forum.

John

============================
UPDATE 12/5/2011

OK went to the range and fired about 60 rounds and no more blown primers

. I still see the little brass tits about 10% of the time across the winchester 7.62x51 and the prvi partisan .308 168 grain. I don't know if this is normal for this rifle. I will reload and use the CCI 7.62 primers. The factory trigger is horrendous...

 

[venharis]

Re: PWS MK214 and some blown primers


I think whats going on is that the really light hammers on the after market triggers are good to reduce lock time but the lack of inertia and mass to "hold" down the primer during ignition is whats causing the problem. Looks like I'll just save myself 200 bucks and do a trigger job on the orginal...