CCI 5.56 Military primer

[Slamfire]

If you look at post 41, WildDeuce posted pictures of factory new W/W ammo that slamfired in his rifle.

http://www.thehighroad.org/showthread.php?p=4627417

I have never heard of an out of battery slamfire with an AR. I have one in battery slamfire, and same day, same firing point, next relay, my shooting bud also had one. Mine was with WSR, his with Federal small rifle.

You are most likely to have a slamfire when you put a round in the chamber and drop the bolt.

Enough of these have happened in the standing stage of Highpower, that the rules now forbid you to load the rifle on the stool. Some folks used to put the muzzle of their AR on their stool, load a round, drop the bolt. I heard one shooter put a bullet through everything in his stool!. Another bud of mine was shooting standing next to a Junior. He said "the Junior was loading his rifle "in a dangerous way"". I suspect Junior lifted the rifle up to his head (so he could see the chamber) , put a round in the chamber with the rifle parallel to the line, and dropped the bolt on the round. (I have seen guys doing this). In this instance the rifle slamfired and the round went throught the air between my friends left arm and his body and blasted a divot out of the ground.

The NRA rules have been changed such that if you discharge a round into the ground within 10 feet of the line (might be 10 yards), you will be sent home.

This was due to slamfires in AR's.

I have been using CCI#41's in my AR's and they shoot just fine. I have never shot a 200 at 600 yards with the .223, but I have come close. End of July I shot a 197 with a load of 80 SMK 23.5 grs N140, W/W cases CCI#41 primers. I was working on a 199 until the last two shots were 9's. It was so hot............

I don't have any chronograph data on the #41's, but I have not had to cut my loads from the old nickel WSR. However the new brass finish WSR, those primers pierce so easily with loads that never bothered the nickel plated ones, that I ain't using them anymore.

Back in the bad old days when good two stage triggers were not around, tuned single stage triggers would occansionally double. You would hear this burp in rapid fire. At the end of the string we would call down to the pits that their might be a missing shot. However, with the .223, the shots were always on paper. Unlike the days of the M1a, when a 308 doubled, the second shot was on its way to the moon.

I personnally saw shooters have doubles with Jewel triggers. Call it triples. The shooter had adjusted the Jewel to give an extra light trigger pull with minimum sear engagement. The hammer followed the bolt and I saw a string of empty cases tumbling out. I was next to the shooter when it happened. Since it also happened on his alibi string, his chances of winning were over for the day.

 

[243winxb]

post 41, WildDeuce posted pictures

Its a ZM parts gun. The bold face looks funny to me after downloading and editing the photos. Looks like the firing pin hole has been peened forward from the firing pin when dry firing. I wonder if the correct spring is in the ejector? In single shot bolt rifles its been know that if you trim the spring the fired round will not eject as hard or at all. The ejector should cusion the fall of the bolt as it makes contact with the loaded round. The photos of the slamfired rounds show NO firing pin strike. I would blame the slamfires on a parts gun that this is not properly fitted.

 

[Slamfire]

The photos of the slamfired rounds show NO firing pin strike. I would blame the slamfires on a parts gun that this is not properly fitted

What sort of indentation were you expecting?

I have examined the primers of rounds that slamfired in a AR. Or rather I picked up all my brass, and in there was the slamfire round. There was no distinctive differences between any of the cases. And I did pick up my bud's brass case, the one that slamfired. And it looked just as normal as any other case.

And that included the 30-06 case that slamfired out of battery in my M1 Garand. The primer looked absolutely normal. Normal indentation, normal protrusion, normal edges.

The only difference from normal was that the front third (half?) of the case was missing. Best I could tell the Garand slamfired out of battery, the cartridge case was blown backward out of the chamber until the case walls could no longer hold the pressure.

And the detached back of my frigging receiver shattered my glasses and cut my face.

As for WildDeuce's rifle, the pictures show an operating rod attached to the carrier location. That would increase the mass of the bolt/carrier. In my opinion that means the whole assembly has more forward momentum than a regular keyed carrier. If that is true, than the bolt goes forward faster than normal.

Which means the firing pin rebounds off that primer at a faster speed.

 

[243winxb]

I have examined the primers of rounds that slamfired in a AR. Or rather I picked up all my brass, and in there was the slamfire round. There was no distinctive differences between any of the cases. And I did pick up my bud's brass case, the one that slamfired. And it looked just as normal as any other case.

if they all looked the same, had a firing pin indentation, then it was not a slamfire, but a trigger sear problem. Top 2 are slamfire, middle 2 normal, bottom 2 unfired. 2 on left are slamfire, on the right normal.

 

[243winxb]

These photos belong to WildDeuce, i hope he don't mind. Thank you.

 

[Slamfire]

These photos belong to WildDeuce, i hope he don't mind. Thank you

I asked WildDeuce if I could copy and use his photographs, and he gave permission. I don't think he would be upset if others borrowed.

if they all looked the same, had a firing pin indentation, then it was not a slamfire, but a trigger sear

This is one of the things about slamfires, how do you know it really was a slamfire and not a high primer, or a sear issue.?

With reloads, how do you prove you did not have a high primer?. Well, you have to take people at their word when they say they inspect their primed cases for high primers.

With factory ammunition, good American made stuff, high primers, never seen one.

A mechanical malfunction, like a sear, tend to repeat. And repeat often.

The NM AR in question has an Armalite two stage trigger set up the USMC armorers. If you take a rifle to them, at Camp Perry, they will do a free trigger job. That trigger has never malfunctioned, and I am on the second barrel on that rifle. I don't think it was a sear problem.

Incidentally, I always put the safety on each shot in the standing fire stage. I roll the safety on when I take the rifle off my shoulder. (I also try to do this for sighting shots in the rapids, and before the first shot in rapid fire, and between shots at 600 yards. But there have been occasions when I got out of sequence at 600 yards) And that includes M1a's and Garands. I want the chance of an accidental discharge to be zero, if I drop the rifle, or when I chamber a round. It has been awhile, but I have no recollection of doing anything different that day.

My bud, repairs small arms for the military. When he is not at Depot, he is at military bases fixing all sorts of small arms. He knows his small arms. He has never indicated to me a repeat of his slamfire. So I don't think he had a sear problem.

My Garand, I replaced the barrel and receiver. Same trigger group. It has never followed. Have not shot enough to replace the barrel. Only shoot it about twice a year, but it has been around ten years. I have confidence it was not a sear issue.

I cannot explain the rings on WildDuece's primers. But I don't doubt his story.

 

[ocabj]

I've had problems with Winchester SR in the AR15 platform.

No slamfires, but I've had quite a few pierced primers, even in mild loads.

For some reason, the Winchester SR primers don't hold up well in the AR15.

That's why I started buying CCI small rifle primers (400 and BR4) and now Remington 7-1/2.