5.56 AR Primer

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I just found out that cci makes a 5.56 ar specific primer, their #34 to eliminate slam fires. I loaded some with standard small rifle primers and I'm wondering now if they will be ok for my AR.
 
They should be fine, if you don't crush them seating them in crimped GI cases like I used to do years ago.

I have been using Standard CCI SR primers in AR's and Mini-14's since 1970.

So far, none have blown up.

Like I said earlier though, I did have a few problems with doubling when I first started reloading .223. I was crushing primers in GI cases with reamed out crimp, and seating with a press primer arm.
They sometimes went in kicking & screaming, but by golly they went in!!

Finally figured out a primer pocker swaging tool, and a RCBS hand primer tool was a better way to fly without crushing primer cups flat.
Never had another double since then.

BTW: A slam fire in an AR-15 is not the end of the world like it is in some other guns.
An AR-15 firing pin is too short to set off a primer, unless the bolt is fully & safely locked shut.
So what you get is an unexpected shot (or double shot) when chambering, not an explosion.

rc
 
I have not heard of any out of battery slamfires in AR's and I don't know how it could happen. I have had, seen another, and heard of in battery slamfires.

Mine occurred during the NRA standing slowfire stage of a highpower match. I was using the brass colored WSR primers. Winchester nickle primers used to be the primer I preferred to use, never had an issue, but these brass colored WSR are thin and pierce easy. My AR also slamfired, in battery.

The bud with whom I was squadded, his AR slamfired with a Federal primer, during his standing relay.

What characterizes the standing stage from all other stages is that the rifle is loaded single shot while standing. (That you shoot the standing stage while standing ought to be obvious from the name.) However because you are standing, most people lower the muzzle, drop the round in the chamber, and hit the bolt release while the muzzle is down. Enough slamfires occur standing that it has become evident that the little extra bolt acceleration due to gravity is enough to set off the occasional primer.

The NRA banned loading on the stool. I used to see shooters balancing their muzzles on their shooting stool, drop a round, hit the bolt release. I will bet someone’s rifle slamfired through the stool and that is why it is now illegal to load on the stool. I can just imagine the consternation on the line when some poor schmuck blew out the bottom of his shooting stool with all his equipment inside. I hope no one shot their foot. A 223 round in the foot would cause a nasty wound.

I have stopped dropping the bolt on a round in the chamber, I put a round in the chamber and lower the bolt half way before letting go. I also do this with the rifle sort of level.

You will get DQ'd if your round lands in front of the firing line. I want whatever future AR slamfires I might have to hit the berm. Loosing 10 points is better than having to go home.

I also use CCI #41 primers as they have thick cups and are hard to pierce. These are excellent primers in the AR and I shoot HM scores (seldom HM standing scores anymore) all the way out to 600 yards with the things.

My recommendation, just use up your primers, always feed rounds from the magazine to slow the bolt, if you drop a round in the chamber, lower the bolt half way before letting go.

And do not assume for an instant that you won't have a slamfire. When you load these things, you must ensure that nothing is in line with your muzzle that you don't want dead. Just in case.
 
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Keep your firing pin clean and lightly oiled, primers below flush. I'm using WLR in 308 with no problems so far. I have the CCI, but not used them yet. Anytime you chamber a round (any gun) make sure the muzzle is pointed in a safe direction. Unless your shooting comp, don't worry about the fancy primers.
 
Unless your shooting comp, don't worry about the fancy primers.
Unless, ...unless that is, you are shooting a Garand and/or an M1A. There, I never recommend anything less than CCI (never Federal), and always watch for other shooters letting a bolt fly full-stroke/freely home on a loose cartridge.
 
So far, none have blown up.

I have been assured by at least three different internet experts that using anything but primers specifically designed for ARs can and will result in damage to the firearm and/or injury to the shooter.

This did not apply before the introduction of "hard" primers, but is now part of the US code.

I've used most primers available, including the copper cupped Wolfs. Still have all my rifles and fingers.
 
About a year ago I traveled 75 miles to the nearest Cabelas to get primers.
When I got home I found that the counter guy had packaged Small Rifle Magnum primers.

I posted here & found that a good number of members said that that's what they use anyway.
Their advise was to start slow & work it up.

I think that's great advise anytime you change primers.
So be it, small rifle primers, Small Rifle Magnum primers, or 5.56 primers, just start slow & work it up.

Stay safe my friends!
 
all self loaders have the potential for slam fires, reguardless of primer type. In my experience as long as you properly seat the primers just below flush plus a well maintained in spec weapon then you have minimized the chances of a slam fire. Thicker cup primers to me are a solution in search of a problem.
 
There is no truth to the "slam fire" issue.

The CCI No. 41 Primer "For 5.56mm Ammunition" is specifically designed for the higher pressure of the 5.56mm cartridge compared to common commercial .223 Remington cartridges.

The primer cup is constructed of thicker metal so the primer won't "blow out" and deposit debris in the trigger action of an AR series rifle, which can jam the trigger action, and require disassembly of the lower receiver to remove the debris. (This is why "anti-walk" trigger and sear pins are not a good idea in a fighting gun because they require a small Allen wrench to unscrew and remove versus simply pushing out the two pins with the tip of a bullet cartridge.)

(Blown primers are commonly encountered with 5.56mm ammo that is fired in .223 chambers, especially when the 5.56mm ammo is loaded with commercial small rifle primers.)

Unless you're loading .223 Remington ammo to 5.56mm velocities then you don't need to use the CCI No. 41 primer. Common small rifle primers are fine.

The CCI No. 41 primer usually requires a little more effort to seat than commercial small rifle primers, especially when loading military cases that have had the primer crimp swaged, apparently due to the resistance of the thicker primer cup. (Sometimes it feels like you're crushing or damaging the primer.)
 
The primer cup is constructed of thicker metal so the primer won't "blow out" and deposit debris in the trigger action of an AR series rifle,
There is no evidence to suggest that.
Here is what CCI says about it:
http://www.cci-ammunition.com/products/primers/primers.aspx?id=30

All rifle primer cups are able to contain far more pressure then any common rifle cartridge can safely produce.

If primer primer cup fails, the case head can't be too far behind, as they are both made out of pretty much the same material.

rc
 
So what do you call my experience if not a slam fire?
Your experience may be the result of a high primer (or "other factors" (as described by CCI, below) that you have not identified).

Here is what CCI says about it:

"Military-style semi-auto rifles seldom have firing pin retraction springs. If care is not used in assembling ammunition, a “slam-fire” can occur before the bolt locks. The military arsenals accomplish this using different techniques and components—including different primer sensitivity specifications—from their commercial counterparts. CCI makes rifle primers for commercial sale that matches military sensitivity specs that reduce the chance of a slam-fire when other factors go out of control*. [emphasis added] If you’re reloading for a military semi-auto, look to CCI Military primers. *Effective slam-fire prevention requires more than special primers. Headspace, chamber condition, firing pin shape and protrusion, bolt velocity, cartridge case condition, and other factors can affect slam-fire potential."

All rifle primer cups are able to contain far more pressure then any common rifle cartridge can safely produce.

The evidence suggests otherwise - which is why blown primers are commonly encountered when firing 5.56mm ammo in AR's chambered for ".223 Remington", and the debris becomes lodged in the trigger mechanism disabling it. Just ask any experienced AR instructor.
 
I just found out that cci makes a 5.56 ar specific primer, their #34 to eliminate slam fires. I loaded some with standard small rifle primers and I'm wondering now if they will be ok for my AR.
I hope that's a typo because the CCI #34 primers are LR primers and won't fit in your .223/5.56mm ammo. As written above, you will need the CCI #41 primers which are made for small rifle primer cases. I use the #34 primers for making my 30-06 M1 Garand ammo and find them no harder to seat than other primers.
 
which is why blown primers are commonly encountered when firing 5.56mm ammo in AR's chambered for ".223 Remington", and the debris becomes lodged in the trigger mechanism
Thats not what I have seen.
What I have seen is, the whole primer falls out of the case and gets caught in the trigger mechanism.

That is not a primer cup failure.
That is an expanded primer pocket in the case.

rc
 
From the CCI web site.
CCI® No. 34 and No. 41 MILITARY RIFLE PRIMERS


Military-style semi-auto rifles seldom have firing pin retraction springs. If care is not used in assembling ammunition, a “slam-fire” can occur before the bolt locks. The military arsenals accomplish this using different techniques and components—including different primer sensitivity specifications—from their commercial counterparts. CCI makes rifle primers for commercial sale that matches military sensitivity specs that reduce the chance of a slam-fire when other factors go out of control*. If you’re reloading for a military semi-auto, look to CCI Military primers.
*Effective slam-fire prevention requires more than special primers. Headspace, chamber condition, firing pin shape and protrusion, bolt velocity, cartridge case condition, and other factors can affect slam-fire potential.

Remington 7 1/2 primers are also I believe a "mil spec" primer developed when their original 6 1/2 SR primer were found to pierce under the 223/5.56 pressures..
There was at one time a warning against using the 6.5 SR in the 223 on Remingtons web site and IIRC on the box.
 
Mr Dodson,

It appears to me you have read more into CCI's statement than you should have.


"Military-style semi-auto rifles seldom have firing pin retraction springs. If care is not used in assembling ammunition, a “slam-fire” can occur before the bolt locks. The military arsenals accomplish this using different techniques and components—including different primer sensitivity specifications—from their commercial counterparts. CCI makes rifle primers for commercial sale that matches military sensitivity specs that reduce the chance of a slam-fire when other factors go out of control*. [emphasis added] If you’re reloading for a military semi-auto, look to CCI Military primers. *Effective slam-fire prevention requires more than special primers. Headspace, chamber condition, firing pin shape and protrusion, bolt velocity, cartridge case condition, and other factors can affect slam-fire potential."

What this tells me is if you have a slam fire using one of our (CCI) MIL spec primers, don't come crying to us lawyer wise.

The High Power community has been aware of the slam fire issue found with GI type of gas guns. Free floating firing pins are a fact. The problem is when a round is chambered, there will be a "dimple" on the primer from being hit by the foreward motion of the bolt and its firing pin. It matters not who's ammo it is. GI ammo will also have the "dimple". It doesn't matter if the round is stripped from the mag or loaded by letting the bolt close on a round.

It also appears using Federal primers seem to have a increased number of slam fires over the use of Remington 7 1/2's or CCI primers including the Mil Spec, both large and small.

We also know using Federal Gold Match primers will reduce group size based on uniformity if nothing else. So High Power shooters are tempted to use the Fed G/M primers in their gas guns, both the 223's and 30 cals. The Federal primer is overly sensitive to firing pin hits even as little as the "dimple".

To further an example of the Federal Primers being sensitive, if you have a wheel gun which will not always set a CCI primer off on the first firing pin hit the switch to Fed pistol primers. This will normally over come the problem with cartridge discharge on the first go around. Besides a little Unique in a 38 case with a Ferderal Primer makes for a good shooting round in most of the bullet weights anyways.

Lastly, High Power dhooters are often times very careful and uniform reloaders. The reason is we don't want to damage our match rifle by doing something which can be avoided. I would submit Slam Fire checked primer depth before powdering and loading the ammo. Slam Fire is a respected member of THR with valued opinions. What you did Mr Dobson is leave no other explanation than poor reloading habits as the reason Slam Fire had a slam fire. At least the way I took it reading your posts. Life is not allways just black and white.
 
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