First Slam Fire

[vinniedelpino]

Went to the range today and had my first slam fire. Round went through the chronograph about six inches from the center of the target, but shook me up nonetheless.

Fed srp 6 creed brass necked up to 6.5
Winchester (white box vintage) srp

Any ideas what the hell happened? Ive always used cci 41s in my gas guns but I'm out. Is this really the issue or can there be something else at play? Not cool.

 

[37L1]

Your primers are to blame. Winchester small rifle primers have thin cups.

Winchester Small Rifle Primers for ARs? - AR15.COM

Firearm Discussion and Resources from AR-15, AK-47, Handguns and more! Buy, Sell, and Trade your Firearms and Gear.

www.ar15.com

 

[smoothy8500]

Was it a slam fire or a double?

 

[vinniedelpino]

Was it a slam fire or a double?

Slam. Safety on and single loaded. Primer was flush too.

When I checked the case it was cratered pretty bad.

 

[Evintos]

Did you chamber the round more than once?

 

[vinniedelpino]

Did you chamber the round more than once?

Nope.

 

[charnicus]

Other than primer choice, I believe it’s said somewhere that single loading is an instance where slam fires are more likely to occur. Loading from a mag helps to slow the bolt. This assumes you finagled the round in the chamber and full sended the bolt.

 

[vinniedelpino]

Other than primer choice, I believe it’s said somewhere that single loading is an instance where slam fires are more likely to occur. Loading from a mag helps to slow the bolt. This assumes you finagled the round in the chamber and full sended the bolt.

That's exactly what I did and I figured the bolt would be at max velocity on closing this way.

I'm going to submit to rape and buy 1k No. 41 primers on gunbroker and play around with it a little bit more. I'm just a little bit concerned about the situation.

Any thoughts on a Ti firing pin? I'd prefer to play this safe. My son shoots my rifles.

 

[charnicus]

I’d just see what happens with the CCIs. Also I’d recommend just single loading from the mag too.

 

[OREGUN]

Clean the firing pin, springs, channel, etc. No damage? More likely to cause pierced primers than slam fires.

Primer pockets cleaned and primers seated BELOW “flush” (your term). A seated primer is not “flush
With the base but slightly shy of it. This is very likely your cause.

Brass full length sized?…my AR-10 variants often require small base sizing to get them to run reliably on reloads.

With all that said, even a slam fire is not necessarily dangerous as long as rule #2 is followed.

 

[Halfnutz]

Not much experience with other large frame AR's but mine (LT) has a sping on the firing pin to help with this. Maybe check into firing pin options for yours. I kinda thought this was common on large frame.
I also seat primers .005 to .006 below flush.

 

[Precision Underground]

Primer should be deeper than flush. Not sure if you just mixed up terminology but seating ar primers flush can cause this, or so it is said.

 

[vinniedelpino]

Primer should be deeper than flush. Not sure if you just mixed up terminology but seating ar primers flush can cause this, or so it is said.

they were fully seated in cleaned primer pockets

 

[larryh128]

Slam fires can happen with standard primers as you loaded it. I've never had an issue yet using CCI400's when loading from a mag. (yet)CCI 450 or 41's are the best bet.

 

[Ledzep]

I remember about 12 years back as I was getting into the CMP/M1 Garand craze that folks recommended against Wichester primers for use in M1's because the floating firing pin would often set them off.

 

[MarkCO]

I use a Ti firing pin in my match guns to mitigate slam fires. In a few of my ARs, I can create a slam fire with Win primers and a standard firing pin. I can not with a Ti firing pin.

 

[Ravenworks]

That's exactly what I did and I figured the bolt would be at max velocity on closing this way.

I'm going to submit to rape and buy 1k No. 41 primers on gunbroker and play around with it a little bit more. I'm just a little bit concerned about the situation.

Any thoughts on a Ti firing pin? I'd prefer to play this safe. My son shoots my rifles.

Midway has had 41's for about 2 months.
They may say sold out but keep checking as the release blocks of them throughout the day.

I use a Ti firing pin in my match guns to mitigate slam fires. In a few of my ARs, I can create a slam fire with Win primers and a standard firing pin. I can not with a Ti firing pin.

Although I use TI firing pins they are NOT a problem solver.
Why is it that all the military weapons don't have them?

 

[MarkCO]

Although I use TI firing pins they are NOT a problem solver.
Why is it that all the military weapons don't have them?

Because they are not as durable and they use CCI 41 primers. A Ti pin certainly mitigates the problem when using standard primers. Common sense solutions trump mil-spec everyday.

 

[CaptNemo]

Federal makes a Gold Medal Match AR primer as well.

 

[OREGUN]

Brownells has AR primers this morning.

 

[BullGear]

How many rounds went through the gun that day? I guess anything could happen with that 1 primer.

Must have been a Friday afternoon primer.......

 

[msgriff]

Use a Bob Sled if you're going to do a lot of single loading.

 

[TheGerman]

If it doubled, you'd need to check/clean out/lube your FCG and springs.

Since this sounds like a slamfire, chances are the primer was too high as well as a thinner/sensitive variety. Generally, if the primer is seated deep enough, the thickness of it is mostly moot as a slamfire has an extremely low chance of happening, thin or not. Seat the primer too high (i.e. flush with the case) and the pressure from the firing pin coming slightly forward on an AR platform will set it off.

 

[iceng]

Wait. Slam fire. What gun ? You said gas gun. AR ?

Slam fire and firing pin. Only suggestion I have is to load the round into the mag before sending bolt home, don't just put it ontop of the mag and let the bolt slam.

The only fix I'm aware of is using a spring on your firing pin for ar10 platforms.

 

[vinniedelpino]

How many rounds went through the gun that day? I guess anything could happen with that 1 primer.

Must have been a Friday afternoon primer.......

One. The slam fire. I immediately checked to make sure the firing pin moved freely and it did.

go figure.