[RavenVT100]

Simply put: Is this primer hard enough for use in an AR, or will it precipitate a slam-fire?

I have heard that CCI's military primers will solve this problem but I cannot find any at the moment. That, and I have been using federal match ammo with ARs and have had no issues thus far, knock on wood.

Am I risking anything by reloading for the AR with these primers, provided they are seated to correct depth?

Thanks.

[sargenv]

Um, doubtful that you will have any issues. Almost all of the people I know who shoot AR's, Mini's etc load their ammo with Winchester SR primers. It's what's available and many of them use the small rifle primers for high pressure pistol ammo (38 Super +P+, 9 Major, and 40 S&W). The WSR and WSP are identical when it comes to amount of priming mix. However the cup on the WSR's are a tad thicker to accomodate the higher pressures associated with rifle loads.

Vince

[GRIZ22]

I have used CCI reloading for ARs, Mini 14s, and AUGs with no problem. The only 223 I have experienced any slam fires (including use of WW, RP, and Federal ammo) with is an AUG which seems to need milspec or CCI primers.

[mc223]

The link below contains a lot of info including primer cup thickness.

http://www.radomski.us/njhp/cart_tech.htm

[ATAShooter]

I use WSR in mine, and 7800 rounds so far, and no problems.

[hagar]

I have seen a number of slamfires on the highpower ranges, and I make it a point to go ask what primer they were using. EVERY single one was caused by a Winchester small rifle primer. Use either a Remington 7.5 or a CCI BR4 primer and forget about it. The CCI #41 primers, supposedly made for the AR, are the worst junk I have ever shot in my AR's. First I blew out the bottom of one of my mags shooting a very mild handload in a 16 inch Bushmaster upper, figured it must have been the upper, and then I pierced some more primers in one of my highpower rifles. 99% of them show no signs of pressure, and then all of a sudden you pop a primer, that is bad news and bad quailty control.

[RavenVT100]

hagar,

In these slam fires you witnessed, was there any indication of improper primer seating depth or were you certain that this was caused by the primer being too soft for the free floated pin?

Thanks.

[Ida Noski]

Hagar,
I've been on those ranges with you and seen some of them too!
For what it's worth, I have used nothing but Winchester primers for not only my Highpower ammo but even my plinking and SHTF .223 for my midlength carbine.
I have never experienced a slam fire.
Primer hardness is not the primary factor causing this phenomenon. What is the most critical is primer seating depth. I use a primer pocket uniformer from Sinclair http://www.sinclairintl.com/cgi-bin/category.cgi?category=RECPUN&type=store
This is a self-limiting process which ensures that each primer is seated to the correct depth to eliminate the slam-fire.

Hold Hard!

Jim

[byf43]

WSR primers are what I've used in my AR for many years.
I've also used the Federal 205M primer, with NO problems.

I am of the opinion that slamfires are more an issue of primers not seated deep enough for several reasons, including failure to clean the primer pocket and having some 'crud' between the primer and the bottom of the primer pocket.
Not taking the time to properly seat the primer below the case head is another reason and that could be caused by several other issues, including not paying attention to detail, (read as watching TV, listening to the wife/kids/S.O., etc.)

Thanks for reading.

[tmag]

I bought a thousand of these before I heard anything about the thickness. I've experimented a little with them (and achieved good accuracy), but mostly they are my plinking round primer.

They do begin to show signs before the 7.5 or the #41 primers do. For that reason I don't load any high pressure 5.56-like rounds with them.

[crux]

Was there a bad batch of WSR primers a while back? I seem to remember reading something about this, but can't recall. If so, I've got had 1K of these. They smoke the primer indentions with starting loads on occasion and don't even ask about upper end loads. I've still got almost 900 of these. I don't think this is normal. I like BR-4s, CCI 450s, Rem 7.5s, and Fed 205Ms.

[RavenVT100]

One thing I have noticed starting out is that primers are not too terribly expensive. I will give these a shot (no pun intended) with light loads and see how they fare.

[RavenVT100]

I'd like to resurrect this thread to report my results.

I loaded 50 of these with several starting loads. Using Sierra Match Kings @69gr, I loaded and tested 23.5, 23.8, and 24.2 grains of Varget, respectively.

ALL of the primer pockets have dimples extending back out from the crater left by the firing pin. Two of the pockets on the 23.8 grain loads (out of 25) are pierced, and blackened.

For reference, the starting load for Varget with this type of bullet, as per the Lyman manual, is 23.4.

What is going on here?

[donttellthewife]

What's the brass like, could the primer pocket be out of spec (larger) allowing the primer to move rearwards upon firing. I have found oversized primer pockets on 308 brass before, not sure what caused it. I figured it was to soft of brass in the base of the case

[RavenVT100]

Found two more, out of the whole batch that had pierced primers. That means out of fifty of these primers, four were pierced under starting pressures. This doesn't look good. The cases do not have any signs of overpressure and the primers themselves don't look flattened at all.

donttellthewife:

The brass is federal lake city, headstamp LC 01 (Nato). I swaged the pockets just enough to get rid of the crimp. Other than that nothing has been done. Primers were seated to within 0.006-0.008" below flush.

[hagar]

I had pierced primers with my 17 Remington and winchester primers even with starting loads. That was years before I started shooting highpower. The people on the varmint hunting forum I frequented all recommended Remington 7.5 primers, and I have been using them, BR4 and russian primers exclusively since then. Wish I could find some more of those russian primers, they were cheap and GOOD!

[The-Fly]

odd, i've never had problems with WSR primers. I use mainly winchester and RP brass. My varmint load in 223 is a fairly warm (read max load per book) of 50gr nosler with 25.5gr of 2230 behind it.

[RavenVT100]

TheFly: Are you shooting these in an AR?

I was really, really disappointed about this. Not only will I have to buy new primers now, but I'll need to check my firing pin for damage.

Next on my list to try are the Remington 7.5s.

[donttellthewife]

Just out of curiosity decap the cases and check the primer pocket dia. and unifom roundness. I've used the RCBS swager and the dillon, the RCBS left a smaller opening than the dillon, a difference I could feel when seating the primer. Just a thought

[mc223]

Now that you have pierced primers you need to get a new firing pin. as the gas that escaped from the primer has burned your firing pin tip and will just lead to more peirced primers.
Go back near the begining of this thread go to the primer cup thickness link. Pick a primer with the thickest cup and order some.
Rem 7-1/2 are very scarce right now.
CCI br-4 is a good choice as is the 450
Fed 205 standard are working good for me right now.

The very first and last peirced primer I had was with WSR and 748.
I stopped using both, went to the Feds and Varget, N-140/N-540 for the 69SMK. I have been using 25.3g of any of the above wih no sign of pressure, exceptional accuracy, clean brass. I load 75g A-Max molys at more than 25.3 with great result. 60g V-Max over 26g varget is my varmint pet for the 1 in 9 twist Bushy.

[The-Fly]

RavenVT100, yes, all my 223 guns are AR's.

[RavenVT100]

I've already noticed the firing pin damage. Fortunately they're only $7.50 from Bushmaster.

Is there a chance my bolt could be harmed as well, or would this only happen with a seriously bad blown primer?

I'm going to order the FP protrusion gauge as well.

Just out of curiosity decap the cases and check the primer pocket dia. and unifom roundness. I've used the RCBS swager and the dillon, the RCBS left a smaller opening than the dillon, a difference I could feel when seating the primer. Just a thought

I'll do that when I come home from work. Good idea.

However, how's the roundness going to affect this either way?

[Quintin Likely]

I've heard of mixed results with WSRs in AR15s. Mostly a tendency to pierce when shooting cruiser weight bullets. I use Remington 7-1/2s or CCI BR4s.

[crux]

Sounds strange to say but, I'm glad I'm not the only one having these issues. I've had to replace a firing pin also. I've written off the WSR.

[RavenVT100]

One theory I have is that the primers (WSRs) pierce when the firing pin protrusion is at the higher end of its specified range. I am going to measure protrusion when my gauge comes to see if this is the case.

[SlamFire1]

Slamfires are very real phenomena with semiautomatic mechanisms. People attribute slamfires to mechanical things, like stuck firing pins, grease in the firing pin hole, hammer following the bolt, all of which will cause a slamfire, but when it comes to primer sensitivity, folks just will not acknowledge this as a factor, instead you get absolute denial.

Imagine this, you have a primer and a firing pin with sufficient energy to ignite the primer. What happens when the firing pin hits the primer?; the primer goes off. Imagine you have a free floating firing pin attached to a rapidly moving bolt carrier and a round is being fed into the chamber. And before the trigger is pulled the firing pin hits the primer with sufficient energy to ignite the primer. What happens?; the primer goes off. If the primer goes off before the bolt is in battery you have an “out of battery” incident. That is likely to be a destructive event.

The SKS with a free floating firing pin is particularly susceptible to slamfires. So is the M1 Garand and the M14 mechanism. The original M16 configuration had slamfires in service so the military redesigned the firing pin to make it lighter. If you notice the FN/FAL firing pin is spring loaded, so are Russian SKS designs, and so are the AR10 designs. All needed to keep a sensitive primer going off when hit by a rapidly moving firing pin.

I used sheaves of WSR primers when they were nickel plated. They were excellent But around 1999, Winchester changed their primer by eliminating the “nickel” finish to a “brass” finish. I called Winchester to find out what this change has done to primer sensititivity. Per telephone conversation with Mr. Chris Huseman at Winchester Group, Olin Corporation 618-258-3565, the old WLR primer had a zinc plating on the cup. Mr. Huseman said the material was zinc, (even though I thought it was nickel). Anyway, Winchester removed that plating, perhaps with other changes, to make their primers more sensitive. The product change was specifically targeted to “combat light firing pin hits and off center strikes.” Which is of course is fine for bolt guns, revolvers, or monkeyed with auto pistols, but is something you do not need in a military action or a gas gun. The result of making the cups thinner is pierced primers and the occasional slamfire.

I had one slamfire in the AR, I dropped a round in the chamber, during the standing stage, and released the bolt. The round took a divot of dirt out in front of the firing line. It was a new brass WSR primer in the case. The next shooter on my point did the same thing, dropped a .223 round in with a Fed Match primer and also got a slamfire. I seat my rifle primers by hand with a Lee Primer and inspect each primer. I did not have a high primer.

Something to remember about AR’s, if you can, single load through the magazine. If you drop a round in the chamber, hold the bolt back using the charging rod, trip the bolt release, lower the bolt about half way, then release the charging rod. Finally bump the forward assist. It is always good practice to bump the forward assist on the first round, mag fed or port fed.

CCI is the only manufacturer who claims to make a “Mil Spec’ primer. When talked with CCI, I was told that these primers are less sensitive than commercial and are magnum primers. I have used CCI#41 in my match AR’s for years now, shot my absolute best long range scores at Camp Perry with them (didn’t clean the target but came close). I am surprised that someone else has had a problem with them.

Because primer sensitivity equipment is not available (like chronographs), people can’t test primer lots and see the varying levels of energy it takes to ignite primers. They also don’t know the kinetic energy of the free floating firing pin. The “conventional wisdom” is that all primers are the same and therefore slamfires are only due to high primers. This assumption is false, but I don’t have the data to prove it. And neither do the people who insist that primers are all the same, or that primers don’t vary from lot to lot, or even from primer to primer.

I do believe that a high primer will cause a slamfire. But an overly sensitive primer will occasionally ignite even if properly seated. It may be one in 50,000, it might be one in 1,000,000. But it has happened, does happen, will happen.

[g56]

I've only loaded a few thousand, 5,000+ 223 shells for use in my AR-15's, 99% of those with Winchester small rifle primers with no issues of any kind.

Imagine this, you have a primer and a firing pin with sufficient energy to ignite the primer. What happens when the firing pin hits the primer?; the primer goes off. Imagine you have a free floating firing pin attached to a rapidly moving bolt carrier and a round is being fed into the chamber. And before the trigger is pulled the firing pin hits the primer with sufficient energy to ignite the primer. What happens?; the primer goes off. If the primer goes off before the bolt is in battery you have an “out of battery” incident. That is likely to be a destructive event.

One difference with the AR design is that the firing pin in an AR cannot reach the primer till the bolt is locked, so while a slam fire is possible, it shouldn't happen with an open bolt.

[RavenVT100]

So far the ratio of "Winchester primers are not recommended, I get pierced primers all the time with them" and "I have loaded Xthousand rounds with them, they are fine" is around 1:1. It would appear that this really is a problem with some ARs. The question is, why?

[SlamFire1]

Seems to me that 50% of the people reporting a problem with Winchester primers has met an extremely high threshold for showing that there is a problem. Medical drugs fail if there is a one in a million chance (or is it one in ten million?) of an ill effect, and here you have 50%, and that is not good enough for you.?!!

Well let me recommend that you go buy a sheaf of Winchester primers, load your favorite loads, and if they work well, be happy. However, instead, if primer piercing causes you eat up a bunch of $7.50 firing pins, chalk it up to experience, or, if you are particularly stupid, coincidence.

[RavenVT100]

Slamfire: I believe you may have missed where I wrote that I purchased some CCI BR4 primers, with a cup thickness of 0.004" greater than the WSRs. So yes, 50% is far too great for me to want to take chances with.

[whofan]

Let me throw my two cents in here. I have used Winchester Small Rifle, Remington 7.5, and Remington 6.5 primers extensively for my AR's.

I have found that for a given load, the Winchesters flatten out much more. In fact, usually with the same load, the Remington's , either variety, look as good a new--except for the firing pin hit.

I don't know what to make of it. Sometimes I think that the Winchester primers are a bit hotter.

I am well aware of the fact that Rem 7.5's a supposed to have a harder cup and use them when loading "hot". The availablity of Rem 7.5's is quite spotty around here (Springfield, MO) lately, however.

[SlamFire1]

When I get primer piercing with a known load I cut the load. In a .223 I will cut it by a half a grain and see what happens. In my Krieger barreled AR I had to cut a N135 load (using the 69 Sierra) from 23.0 grains N135 to 21.5 grains to stop the new brass WSR primers from piercing. Had to cut all my loads with the brass WSP and got tired of changing out firing pins. I think the last of them have been loaded up and I ain’t buying any more.

Instead I have been using CCI #41’s.

I have to replace a M70 bolt because the firing pin hole was so large that the primer would flow into it. I guess that if someone ever pierced enough primers erosion would enlarge the firing pin hole, and that would require the bolt to be replaced.