Primer Failure Question

[Dutch3]

I had this happen at Spenceville yesterday. .308/7.62x51 150gr FMJ reload. Light charge (40.5gr H4895) for a Chilean Modelo 1912.

Another Calgunner there indicated it is probably a bad case. Hard to see in the photo, but there is a pinhole in the primer cup between "R" and "P". I am not sure if a case defect contributed or if it was simply a weak primer. WLR.

I haven't deprimed it yet for a closer look, but curious as to your thoughts?

[Bill Steele]

I get a lot of that exact failure with recent WLR primers in my 308 Win. There have been numerous threads on this subject, so far, Winchester seems to replace the bad lots.

I do have to say I have not had this failure with my premium (new Hornaday and Lapua) brass. The failures always seem to be on cheapo LC and FC mil-surp and FGMM brass, which I use for fouling rounds. It is definitely not pressure related, might be somewhat brass related, but Olin seems to make good regardless.

FWIW, I have had the exact same failures when using WLP in my 10mm loads. In these cases, I only use Starline, so again, maybe yes, maybe no, on the brass contributor effect.

I have a lot of Winchester primers, when I have worked them down, I am moving on. Too much hassle.

[Dutch3]

Thanks,
I haven't researched the lot number, but believe it is among the ones I purchased within the past few months. I have loaded and shot quite a few with them using mixed brass, this is the first failure I have seen.

[drdarrin@sbcglobal.net]

What caused you to notice this? Blow back? Flyer? Reduced recoil/report?
The primer looks a little high? Is it? Was it high before firing?
Any problems seating primers? When I used to use the priming arm on my press, I would sometimes have difficulty seating primers. Catching an edge of the primer can cause the cup to deform, possibly enough to cause this problem.
Was the flash hole obstructed in some way perhaps? If you use walnut or corn cob tumbling media, it is possible a piece was stuck in the flash hole but it hard for me to believe it would be tight enough for the primer to blow back. If it did, I'd expect a flyer.
If the report was normal and the bullet not a flyer, that would indicate ignition occurred normally. If that's the case, then a close examination of the primer cup and primer pocket is in order.

[drdarrin@sbcglobal.net]

What caused you to notice this? Blow back? Flyer? Reduced recoil/report?
The primer looks a little high? Is it? Was it high before firing?
Any problems seating primers? When I used to use the priming arm on my press, I would sometimes have difficulty seating primers. Catching an edge of the primer can cause the cup to deform, possibly enough to cause this problem.
Was the flash hole obstructed in some way perhaps? If you use walnut or corn cob tumbling media, it is possible a piece was stuck in the flash hole but it hard for me to believe it would be tight enough for the primer to blow back. If it did, I'd expect a flyer.
If the report was normal and the bullet not a flyer, that would indicate ignition occurred normally. If that's the case, then a close examination of the primer cup and primer pocket is in order.

[Bill Steele]

To be fair (or at least more accurate), when I say I get a lot, I mean like maybe 1 or 2 in a hundred and then none for maybe a few hundred more. I have not kept close track, unfortunately, but some lots seem worse than others.

The problem has been going on for years, not months. I know of a few guys that had this problem with primers they bought many years ago. I always assumed it must have been either the tool that forms the cups had a burr or the material used to make the cups had imperfections. In any case, while the brass used in the round may affect the failure rate, I don't think it is the root cause.

I have never had this type of failure with Federal, CCI or Remington.

[msnm]

if the primer pocket was not swagged all the way if it is mill brass as it seems to be, that can do it, the primer doesnt look to be seated all the way...but a simple deburring and or a little jigg in the primer pocket with a phillips head on a cordless drill will do it.

[Dutch3]

What caused you to notice this? Blow back? Flyer? Reduced recoil/report?
The primer looks a little high? Is it? Was it high before firing?
Any problems seating primers? When I used to use the priming arm on my press, I would sometimes have difficulty seating primers. Catching an edge of the primer can cause the cup to deform, possibly enough to cause this problem.

Initially, I noticed a reduced report accompanied by gas/noise at the breech. I normally inspect the spent cases from these old guns as a matter of practice. I did look at the unfired remainder of the batch for high primers and didn't note any.

I usually prime on my single stage press, with a "fingertip check" as each case is removed to feel for any priming anomalies. Perhaps I need to be more scientific. After looking at the removed primer and case, I would call it a failed primer, unless it was perhaps a high primer that I missed.






Primer lot is FGL133G, if that means anything. I have about 950 of them left.

[Sac-AR15]

Had one a few trips ago at the range. Figured it was just a dud primer.

[drdarrin@sbcglobal.net]

I would agree with your assessment.
I've given up on my press mounted priming system (single stage as well). I now use the RCBS Hand Priming Tool (shameless plug, I know!) for that step. The "feel" is much better and I seldom if ever "flip" primers (e.g. seat them upside down).

[FLIGHT762]

Contact Winchester, they will probably replace them for you. in over 40 years of reloading, I've run into a couple of bad batches of primers that had a burn through like yours. I do remember reading about recent bad lots of WLR primers.

[Dutch3]

if the primer pocket was not swagged all the way if it is mill brass as it seems to be, that can do it, the primer doesnt look to be seated all the way...but a simple deburring and or a little jigg in the primer pocket with a phillips head on a cordless drill will do it.

There are some NATO/crimped cases in the same reload batch as this one, but this particular case is regular commercial Remington brass.