[GunAdmirer]

Is it really necessary to use an arsenal primer for an AR15 type rifle or will a magnum primer perfom nearly as well? Are they that much tougher and less likely to induce a slam fire.

I have three reasons for asking:
1. I like the silver colored primers. Easy to distinguish reloads from factory.
2. The regular magnum primers are $.20 cheaper per 100 in my area than the arsenal primers. I know it's not that much but....
3. The regular magnum primers are more widely available.

[P0832177]

I use all kinds of primers in the AR. None of my loads press the limits. But, the Rem 7.5 is hard primer meant for loading the 17 Rem.

[1911user]

I'm not sure what you mean by arsenal primers, but I use CCI#41 primers for 223. They are supposed to be mil-spec hard and they are silver. My AR has had no issues with them. They do cost about $2/K more; seems like cheap insurance to me.

[GunAdmirer]

I am talking about CCI #41 primers. The package says "Arsenal Primers" and the primers are gold or brass in color. I purchased them recently from Sportsman's Warehouse.

I haven't had any problems with them. They may be a little harder to seat. I just wonder if they are really necessary and worth the extra expense.

[P0832177]

Use that primers that give you the best results! Do not make choices on internet lore! Let the results guide your choices!

[callgood]

As luck would have it, last night I used the CCI #41 primer for the first time.

In a plain white box with black lettering. "Arsenal Primers" was on the box. They were sort of a gold color, and on my RCBS hand primer it took some stout pressure to seat most. A few went in about the same as the pistol primers I am used to (I uniformed all the primer pockets first). It seemed that sometimes if I seated a little and then rotated the case 90 degrees and finished the stroke they went in easier.

[Khornet]

with standard primers (CCI, Rem, Win) in my AR. Don't see what's the issue. They work fine with ball powders too, so I don't bother with Magnums in .223.

[Rico567]

I use the CCI #34 in .30-06 for the Garand and .308 for the M1A. I use the CCI #41 in .223 for the AR. I never heard the term "arsenal primers" used before. I understand that the primer cup metal is the thickness used in military primers, and that the forumulation of the priming mixture is the same as for the respective magnum primers.
I understood when I started to use these primers that they are insurance against slam-fires caused by the inertia of the free floating (no firing pin spring) firing pins in the rifles named above. I consider the articles I read, and the arguments presented in favor of using these primers to make sense. This information came from several sources, and all of it respectable, certainly not "Internet lore." I bought these primers in 5K sleeves (....as I buy all my primers), and paid the same as the standard or magnum primers.
I never had a slam-fire before I started using them, and have had none since. I regard the switch to these primers for the weapons indicated to be simple insurance, at no real expense to me, other than the bother of keeping two additional types of primers in the cabinet.
On the other hand, I think that millions of rounds have been fired through these types of weapons using ammo with regular primers, to no ill effect. for those who want to take your chances, it's your gun, and your choice.

[GunAdmirer]

I asked CCI. They didn't completely answer my question but gave some helpful information:

I asked:

Is it really necessary to use an arsenal primer for an AR15 type rifle
or will your magnum primer perfom nearly as well?


They responded:

Ballistically, these two primers are the same.

However, there is a differnece in the 'design' of an arsenel type primer
(say, the #41 primer) versus a CCI 450 Magnum. In the #41 primer, there
is a greater distance between the tip of the anvil and the bottom of the
primer cup. This feature helps to prevent slam fires in military style
semi-auto firearms. The same goes for large rifle, CCI#34 versus a CCI
250 primer. Linda