Slam Fires

[giggitygiggity]

Should I be concerned about slam fires when using standard CCI small rifle primers in .223 and shooting them from my AR? Thanks.

 

[R.W.Dale]

It's certainly a possibility, how much of one is up to many factors

do this test

1 with the rifle pointed downrange place a round inside the chamber with the bolt locked back

2 release the bolt

3 eject this round

4 look at the primer and see if YOU'RE comfortable with the size primer divot you see.

 

[Doug b]

You should be concerned with any primer.That said, I have done the krochus test above X 2 on cci small rifle and small mag rifle primers in my bushmaster with no slam fire.That divot gets real big the second time.

 

[rcmodel]

As long as you don't crush the primers flat when you seat them, you should have no problem.

All I have used in semi-auto .223's since I started load it in 1970 have been standard CCI & Winchester primers.

I did experiance doubling at first, until I firgured out I had to remove all the primer crimp before smashing them in with a Rock-Chucker press primer arm.
Switched to swaging primer pockets, and switched to an RCBS hand primer seater.

Since then, it has never happened again in almost 35 years.


The other thing is, a "slam fire" in an AR-15 is really nothing more then two or more shots fired really really fast.

The AR-15 firing pin cannot reach a primer to set it off until the bolt is set back in the bolt carrier and locked.

rc

 

[EddieNFL]

Over about 32 years I've used a lot of CCI 400s without issue; not sure how many but more than 40K. Even used the often rumored soft Federal primers. Doesn't mean it won't happen tomorrow.

Slam fires are always a possibility with free floating FPs. That's why we keep the muzzle oriented downrange. Some folks have the idea that a slam fire will destroy the gun. Don't know where that came from.

 

[matrem]

"Some folks have the idea that a slam fire will destroy the gun. Don't know where that came from."
I think that comes from a misunderstanding/wording of a fire when bolt is not in battery.

 

[BWB]

Perhaps a holdover from M-1 or M-14 where an out of battery slam fire is an unpleasant possibility.

 

[243winxb]

Yes, slam fires can happen with "parts guns" Mismatched springs or parts are the main cause, IMO. Always load from the magazine. Never drop a round into the chamber and let the bolt slam into it. The bolt must alway pickup the round from the magazine, this slows the bolt speed.

 

[NuJudge]

I've shot quite a few thousand .223's through AR's using CCI small rifle primers with no problems. I like loads that have a record of shooting well in any rifle of the caliber, and for .223 AR's it is a 52 or 53gr match bullet, 26.5gr 748, a CCI small rifle primer, and a LC or WW case. Never a slam fire or a double.

If you are going to do the test mentioned above, do it with a primed case, not with a fully loaded cartridge.

 

[EddieNFL]

Never drop a round into the chamber and let the bolt slam into it.

Can't count the thousands of times I've done that. Very common in HP matches. 600 yard ammo doesn't fit in a mag.

 

[delta5]

I have always been told that if you are just hauling your ammo to the range and using it there, those military grade hard primers are totally not needed. They are only needed if the ammo is being used in real combat situations. Why waste the extra money if you dont have too? I suspect this rumor is being perpetuated by the SWAT/SpecOps wannabees...

 

[Doug b]

"If you are going to do the test mentioned above, do it with a primed case, not with a fully loaded cartridge." Your test method is valid if that is what you are shooting,an empty case and a primer.IMO the test krochus uses is more valid as the mass forward of the bolt is pretty important to the results.