The Winchester SR Primer Issue - Revisited

[RavenVT100]

When I first started reloading for the AR, I used Winchester Small Rifle primers, which sporadically pierced, pitting the firing pin in the process. I "solved" this issue by switching to CCI BR4 primers (I haven't run out yet since last year) but I'd like to reopen the discussion because the subject is interesting to me.

When I reported that I was getting pierced primers on my AR with the Winchester Small Rifle primer, I received many answers ranging from that primer type having too thin of a cup to my rifle's headspace being an issue. The CCI BR4 primer has completely solved the problem, however it would be nice to get a conclusive answer as to why this happened with the Winchester primers.

The other step I took was to measure my firing pin protrusion, which was within spec. I also replaced the pitted pin.

I posted about this issue originally over a year ago. Is anyone around now who has "solved" it through means other than switching primers?

 

[rcmodel]

All I have ever used for .223 in AR's and Mini-14's, as well as bolt-guns for about 40 years are either Winchester or CCI SR.
I have never had a pierced primer with any rifle I have owned.

I gotta think this is somehow gun related, rather then primer related.

Or you are just shooting very hot loads!

rcmodel

 

[RavenVT100]

Were your Winchester SRs chrome plated by chance?

The piercing happened on starting loads, by the way. Just over 23.8 grains of Varget under a 69 grain bullet.

 

[243winxb]

What make and model of AR ?? FActory made or a Parts gun? If the Firearm is correct in the first place, there will not be a slam-fire problem. Parts guns just might be the cause of the "new" problem for slam fires. I have never had a slam fire with a factory built rifle, including Colt m16A1, Colt AR15's many mini14's, AR180. To many basement gunsmiths building AR's from parts while watching a "how to do" Video.

 

[RavenVT100]

Ban-compliant config; receiver is a Bushmaster XM15E2S; upper has a 24" 1:9 NATO HBAR. (Yes, 24". It was a good deal at the time).

It is technically a parts gun, but it's Bushmaster parts--the only exception is a DPMS A3 upper. The bolt/BC and the Barrel were headspaced for me by Bushmaster when I purchased them, and I checked firing pin protrusion on the original pin and the new pin that's in it now.

So far it works fine with everything, just not reloads with the Winchester SRs.

 

[243winxb]

Titanium Firing Pin
Titanium is 40% lighter than steel for faster lock time, and greater accuracy. This patented pin is precision machined from Titanium, and finished in a gold tone to distinguish it from standard pins. Increases your safety by reducing the possibility of a "slam fire". This pin will fit either the AR15 or M16.

 

[RavenVT100]

I considered that, but I didn't do it because of what happens with pierced primers on a titanium pin vs a steel pin. And the Ti pin is expensive.

I'm just curious if there's anyone here who has had this problem and solved it without switching primers.

 

[mallc]

5000 plus Win SR and still banging

RvenVT100 -

I had problems getting Winchester SR primers seated on the first batch of .223 I loaded on my Dillon 650. Folks on this board gave me several tips for improving consistency and I put a bunch of them in place at once. At least one of them worked because we've put more than 5000 rounds down range through various ARs and minis in the last year without a miss.

Hope this helps.

Scott

 

[rcmodel]

Were your Winchester SRs chrome plated by chance?

Yes.

rcmodel

 

[ants]

That's a nickel plating, not chrome

I've probably been through 3 or 4 sleeves of 5,000 Winchester small rifle primers lately, all in .223/5.56 and all of them plain brass (not nickeled) with no primer problems of any sort.

I understand what you mean when you say Bushmaster headspaced the bolt and barrel. That doesn't mean the bolt and barrel are properly positioned today because you have a DPMS receiver between them. Is it possible that the barrel is seated poorly in the receiver (not square, not butted fully, whatever) or that the upper wasn't machined square and true, misaligning your bolt and barrel? Have you looked for interference (between the key and gas tube, carrier and magazine, etc)? Even if Bushmaster checked headspace with the bolt fully locked into the barrel extension lugs, is the bolt fully locking in the lugs today? Is something stopping full forward travel of the carrier? Is something stopping full clockwise rotation of the bolt?

I know you may not have the resources, but I have diagnosed AR problems by swapping one part at a time between two rifles. When the symptom travels with the part, I know where to focus my examination.

 

[RavenVT100]

Sorry, nickel. Not sure how I did that.

I've never had any issues with the bolt not locking into the barrel extension. There's never been any issues that I'm aware of with any misalignment. The system has worked fine with every piece of factory ammo I've ever fed it, and the only issues have ever been with these Winchester SR primers.

I was under the impression that the bolt either locks in place against the lugs, or it doesn't, and if it doesn't, you've got a serious problem on your hands.

 

[Sport45]

My firing pin pitted the same way. I ordered a new one, but to keep shooting a buddy suggested stoning the end of the pitted pin flat and then chamfering the edges. I did this and put it back in. I have my new pin (pins actually) but the one I stoned is still in the gun and working with no problems of any kind. Haven't had a pierced primer since and I shoot WSR almost exclusively.

 

[Slamfire]

I posted about this issue originally over a year ago. Is anyone around now who has "solved" it through means other than switching primers?

I used to use the great old nickel plated WSR's and never had any primer piercing issues with them. Then out came the new "brass" Winchester primers. When these came out I talked to Winchester and asked them what they had done. They made their primers more sensitive.

And they pierced with loads that never bothered the nickel plated WSR's. I loaded up a ammo can worth, and found that within every ten rounds, I had at least one pierced primer. These primers ate up a firing pin each highpower match.

Well I cut the loads. I cut them by at least a grain, and am slowly getting those soft shelled primers out of my inventory. And I switched to CCI #41 primers. Those don't pierce with the full power match loads.

I still have a stash of the good old nickel plated WSR's, and used them last year at Perry out to 300 yards. Not one pierced primer with full power loads.

Because high power shooters run hot loads, the brass WSR has pretty much disappeared from the firing line.

You can stone the tip, use Titanium Firing Pins, (which incidentally last about one pierced primer), you can bay at the moon. The only "solution" is to cut your loads or use a thicker shelled primer.