Military primer CCI for .223

[YellowLab]

I got a few thou of the CCI Military primers (from hi-techammo.com, $15 1/k).

Now I learn that they may be 'magnum' primers? How can they be magnum primers without such a marking on the box?

I load milsurp brass, milsurp pulled 55gr bullets and IMR 4895 powder.

How far down should I adjust the powder to compensate for the Military primers? Off the top of my head (notes are on the reloading bench) I *THINK* I load to 26 grains (whatever Modern Reloading lists for IMR 4895).

Adjust charge by -10%?

 

[ocabj]

To be safe, you should reduce for these primers and work up.

But in my opinion, I wouldn't be too concerned about adjusting for the military primers if I were loading them for an AR15 rifle. Even if you load hot, the rifle will handle it since military ammunition is loaded beyond SAAMI spec.

If you are loading for an AR, when you chronograph your loads with those 55gr you will be using, the velocity you will be looking to match will be 3100 fps (in a 16" barrel).

 

[Lennyjoe]

I use H-335 and CCI mag primers for my 55gr FMJ range loads for my AR-15. Meters great. Should give H-335 a try, especially if your loading for 30-30 as well.

 

[Jwar88]

Yes the mil spec primers use a "magnum mix" which is the mil standard for igniting the ball powders the military uses. In general, for setting off ball powders this is a better match.

For 4895, you would be better served with a standard primer for top accuracy, but it won't really make much difference for everyday shooting. Drop the load a grain, or find a load in the manual that uses this primer as a guideline. I recall that the Speer manual I have specifies this primer in some of the loads.

 

[ribbonstone]

Doubt they are magnum primers.,,,but even if they are use them; what other US miltiary rifle round would they have been designed for?

 

[asknight]

You guys are correct in that they are a magnum mix, or magnum class primer. One issue to keep in mind though is that these primers are typically crimped in place in .mil ammo. I have seen a *few* cases where the primers would blow out of the pockets in an otherwise "close-to-max" manual reloading recipe if they were not crimped or staked into the pocket. You may find you need to reduce your standard load, but not by 10%, I feel. Somewhere around 3-5% max reduction (about a grain, depending on load) should offset the hotter primer.

 

[YellowLab]

I am loading the 55gr to 24.5 gr IMR 2895... thats about 1.5 grains under max listed (26 gr).

 

[Travis Two]

Not sure about the "magnum" part of the priming compound but a call to CCI some time ago revealed that these primers have shorter "feet" on the anvil than regular primers in order to make the primer less sensitive by not stressing the compound as much as a regular primer does when seated. In full auto applications this was done to prevent slam fires.