Just a Thought.

[The Blackhawk Kid]

I was at a range with friends shooting our AR-15's. One friend wanted us to witness him using his hand loads that he just got loaded. He put in the mag, and closed the bolt, and BANG! It scared the bejesus outta us! Upon inspection, it was found that my friend used Federal Small rifle primers. M y friend proceeded to shoot some more, and had two more slam fires when the bolt catch was used. This was out of about 250 rounds. I/we suggested that he now use CCI #41 primers, as they are FOR semi auto's with floating firing pins. I have used the #41's & #34's for years. I was just glad nobody was hurt, just scared. Oddly enough I just bought 5K #41's just prior to getting to the range. I sold my bud 1K to start out. He just got his 650 set up and now he's all set. Oh, he is also using commercial brass, now. We all have gone thru learning curves, and this time it wasn't painful. jmho fwiw

 

[Chief 101]

me tinks there is a problem with the firearm....not the ammo

 

[Big Old Boy]

Yep something is not right with the gun!!

 

[Rick Courtright]

Hi,

I'm not an AR guy, so I'll confess my ignorance of many of their quirks straight away.

I do know that CCI primer was developed to help prevent the problem mentioned in the OP, and think it's probably a good idea. However, at the same time, most of the guys I know who shoot ARs seem to be far less than obsessive about cleaning their firearms. So are the other posters also correct in their assessments there's a "gun problem" at the root of things? Guess I'm wondering out loud if the specialty primer just treats a predictable symptom when the cure can't be addressed immediately, as one might expect in heavy use/battlefield conditions, but that problem shouldn't be popping up with properly maintained civilian firearms in the first place?

Rick C

 

[Chief 101]

firing pin should not hit the primer hard enuf to set it off...mine doesn't even leave a mark on the primer

 

[Precision32]

firing pin should not hit the primer

The firing pin will hit the primer each and every time the bolt closes. It's the nature of the floating, unsprung firing pin. The issue goes back to the first auto-loading rifle in the US Arsenal; the M1 rifle. At first they cut the mass of the firing pin, then moved the anvil of the primer to produce a primer LESS sensitive to the strike of the firing pin.

The equivalent of the #41 and #34 primers are the same primers currently used to load USGI ammo and all military ammo since around 1936.

 

[Chuck 100 yd]

What precision32 said +1 The firing pin floats and if soft primers like Federals are used,slam fires are not unheard of. Mill spec primers have heavier cups to prevent that.
Someone makes a light weight Titanium firing pin for the same reason. Remember ,with guns,nothing is written in stone.

 

[DGW1949]

On the other end of that mule, I've yet to see a slam-fire which didn't involve hand loaded ammo and/or a neglected, modified, home-smithed (or otherwise) out of spec gun.
Yes, it's true....regardless of popular opinion, there's valid reasons why certain spring rates were decided on by the manufacturer, and reasons why the US Army teaches recruits NOT to interchange parts from one rifle to another.

As for one primer being a bit easier to set off than another, yes that is true.
Still though, there's been a gazillion rounds of Federal .223 (and .30-cal) that's been fired from semi-autos over the years, plus another half-gazillion of their Gold Medal Match primers (and/or ammo) used in at least three different semi-auto platforms by NRA match shooters, and all without a single mishap which could be attributed to the primer itself.
What that tells me is that while I agree with using a "harder primer" as a means to provide some extra insurance relative to slam fires, if I were actually experiencing such a problem, I for one, would be taking a hard look at my gun....and my reloading practices.

Just my thoughts on the matter.

DGW

 

[Laserbait]

All of my AR's (10, to be precise) leave marks on the primers when the bolt slams into battery (clean, or dirty, doesn't matter). I have been able to set off Federal primers on several occasions by just dropping the bolt onto a primed case (no powder or projectile) for demonstration purposes.

The reason that you don't normally see slamfires with Federal ammo in AR's is because they use a special primer for .223/5.56 and 6.8 SPC cartridges that is harder.