Home Forums Hunting & Shooting AR and Tactical Rifles When should you use a CCI450 vs a CCI400 in a 5.56 load?

His table is flawed.

It only list thickness, but provides no figures regarding the hardness of the various cup materials.

That is the frequently repeated internet wisdom, but is not really true. Ball powders used in the 223 case size are not "hard to ignite", and they don't necessarily need a hot primer. In most of my heavy bullet 223 loads with ball powders, a milder primer like the WSR or S&B SR have been significantly more accurate. Talking about AR15 here, not just bolt guns.

IMO this "ball powder = hot primer" thing is one of those sacred cows that needs to die. I'm pretty sure it came about from the use of H110 in magnum revolver cartridges, and doesn't really apply to most rifle cartridges despite frequent claims to the contrary without evidence.

That's not what my groups tell me.

I also that with such a small case it might not make a difference, so i tested it. The magnum primer really does make a difference with ball powders, especially with H335 and BLC-2. There's no question they shoot better with hot primers.

FWIW...I used to have an old 700 ADL in 222 mag that I had a lot of hang fires with using different ball powders (748, BL-C2, H-335) using various non-mag and mag primers until I tried Win small rifle mag primers.

Winchester doesn't make a small rifle magnum primer.

That is what they used to say about the standard 205 and the 205M, but the new 205MAR has solved that problem, I have switched to them in all but one of my AR's. can't see ever using CCI's again

And groups with most of mine tell me the direct opposite - that milder primers give better accuracy. I see it repeatedly in the 223, Grendel, -08/Creed, and -06 based rounds using powders like TAC, XTerminator, Lever, H414, etc. Not always, but often enough that there is no rule of thumb to follow based on powder choice.

Seems to me it's a lot more about what the rifle prefers than a catch-all statement of "ball powder needs hot primer".

My loading from years ago consistently showed that other than BR4 which supposedly isn't mild, that among Varget, 2230,2250, 748, WC 852 and H380, H4895, IMR4064 and N550 and N540 and a bit of TAC that 450s and M41s consistently were better, to include some use of R7.5 but only on RL15, but that using standard primers the loads opened up.

That may not be the case these days.

Was not aware federal has a specific AR primer now. I don't use Federal that much, but in some instances they have been better primers.

Yeah, I knew that was wrong as soon as I hit post reply. Win small rifle primers...

But the old ones used to be hot enough to be called mags IIRC..

I realized I should clarify this to say I am NOT talking about Rem 6-1/2 primers or any other "low pressure" primer. Just talking about standard CC400, S&B SR, and modern WSR, etc in the small primer cases. Mostly CCI 200 or WLR (which I now avoid) in the large primers.

One example is the 77gr SMK or 75 BTHP in my 223 Wylde over a max load of TAC. With CCI450 primers that rifle shot patterns, not groups. Talking like 3+ MOA. That particular load wasn't great with any primer, but went about 1-1.5 moa with S&B SR primers as the only change, which IMO is a pretty significant difference. My rifle, my loads, etc, but I've seen it too many times to accept the common blanket statement about ball powders. Other times the CCI450 shoots better; IMO you can't know until you try them.

And what you say about primers making a difference is a huge point with me. I've seen em double or more group size. I"ve seen em cut groups in half or more also. Meaning same load, swap primers.

Its one reason I tried to keep on hand at least a few hundred of every primer I could access. You never knew. And yes, we had a load once that worked with Rem 6.5s for some stupid reason.. LOL.

Tac loads for NTIT team ammo at Perry last time I shot was Tac and M41 and 77s. It wasn't great accuracy but it was certainly MOA accuracy just over and under in all the team guns and thats 6 guns as a team firing at the same time and swapping ammo out. Out to 600 but you know all that. Says something at least.

I've had very good result with the S&B's behind TAC as well.
I was under the impression they were on the hotter side.

Never had a slam fire with a federal, but only burned about 2000 of them.

The old federals it was only a matter of time for a slam fire. Or burning a pinhole and into your firing pin. Everyone in high-power competition knew that. It was a given.

I don't know about hotter/cooler, but to me they seemed like clones of Rem 7.5s. Just from a couple velocity readings.

Jeff, I thought you were a big proponent of TAC?