Nujudge,
I don't like CCI primers (they run a bit large in my estimation), but they work with this load.
You were correct on that. A call to CCI's Tech. Dept. several years back, when I had troubles with them, confirmed this. He stated that they manufacture their primer cups diameter on the upper end of the allowable acceptable tolerances in the industry.
It took many failures to fire and other issues before I frustratingly called them to find out. I switched to Federal's and Winchesters, and have never had a problem since. I've heard they recently changed them, and after the last 10-15 yrs. of producing them that way, I wonder why all of a sudden they changed ????
When I posed my problem to the technician, he knew right away what the problem was. Also, the old rumor of them being too hard wasn't the issue at all. It was always that they were too large diameter wise.
Regarding the .223 powder topic.....
Of the ball powders, W748, BLC2, and H335 are probably the most widely used there. Of the stick, or extruded powders, IMR3031, 4198, and maybe 4895 seem to cover the IMR offerings, whereas Varget, being a relatively new powder, seems to show some pretty promising results.
I've heard a lot of guys that like Benchmark, H322, and AA2230, but I haven't used them.
My Lyman manual shows real promising results with AA's 2015. Good velocities, moderate pressure and good (burn) performance in a wide range of bullet weights.
I just bought a Savage 16FS in .223, and after an oversight of not paying attention to the twist rate of 1 in 9, I took it back to the dealer's and switched it for a Remington SPS in the same caliber which had a 1 in 12 twist.
Not that it would make a difference in accuracy necessarily, it's just that lighter varmint bullets (40-55 grs.) don't operate as intended with twist rates as high as those. Many shooting the AR's (1 in 7 & 1 in 8 twist rates), while trying to use lighter varmint bullets, have had "splash wounds" on coyotes when pushing the .223 to standard velocities. They are spinning so fast that they are barely holding together. If a blade of grass is hit, or the hide surface of a coyote, they actually detonate right there, failing to penetrate to the vitals.
The centrifugal forces applied to the bullets at those speeds is phenominal, and the varmint bullets, being of a more fragile design, just can't take it.
Take care,
Bob