RL-10x from the Berger Manual; 50gr. bullets24 in bbl:
21.5gr. RL-10x 3,116 starting 23.7gr. 3,388 max
Sierra Manual, 50gr. bullets, 24 in. bbl:
21gr. RL-10x 3,000 fps starting 24.3gr. 3,400 fps max.
CFE-223 is for the 52/53's, but you can sub the 50 grainers
25.8 CFE-223 3,050fps. starting 27.9gr. 3,300 max.
An Alliant load I have used recently is 27grs. AR-Comp with 50's and 26.5 with 53gr. Hornady V-Maxes.
Its a substitute load for identical charges of Benchmark that clock 3,500-3,550. They're max loads for the 223 AI data with corresponding speeds and identical charge weights (AR-Comp is really comparable to Benchmark, NOT RL-15). Benchmark in the 223 AI Sierra data also is what I've been using in 3 222 Mags with 50gr. Sierra BlitzKings for close to a decade now, with almost parallel velocities and charge weights, probably because the case capacity is identical.
I've personally also used 26.5 grs. 10x with 40gr. bullets, where its better suited. Loads clock 3,800. Ironically, it's the velocity and charge used for 40's in the fairly new Sierra data for the 223 AI. I used 40gr. Ballistic Tips.
There is plenty of 223 data with 223 CFE and the Sierra Manual also lists it in the 223 AI data. Power Pro 2000 MR, IMR 4166, IMR 8208, TAC,Exterminator, and the old Thunderbird LT-32 are some of the newfangleds used with the 222 Magnum, 223 and 223 AI.
The best Alliant 222 Mag powder is RL-15, but it starts with bullets at 68grs. up to the 75's and 77's.... and again, the data for the 223 AI is what I've been using before Sierra shot the data for both cartridges. But lots of guys here have been using 223 AI's here.
The Sierra Edition VI is a great manual if you want pressure tested data for the newest powders with either cartridge; you can go std. 222 Mag pressures into the 223 AI data with some very good direction.
