222 Rem Mag Ackley Improved, for the 14” Contender.


Sep 18, 2011
Warwick, NY & NYC
Does anyone have reloading data for the 222RMAI, with 50 and 55’s? .... in a 14” super contender bbl, that began life as a sloppy throated 223?
Shall I take another leap of faith that I’m not the only Mike Bellm fan shooting this most incredible conversion?

His limited online data is for heavy weights only. The contenders twist is best with 50-55’s.

The P.O. Ackley archives has detailed data for every one of his ai’s, except for the 222RMAI!
I even have his ruler, his hand signed 1960’s instructional letter to me , and the postmarked Manila envelop he used to mail it!
But I have no idea how to use his ruler

Back in the 60’s, the IMR’s started at 4198 and ended with 4350, and that’s what the ruler was calibrated to.

So any helpful leads or data would be appreciated. It’s long throat and larger capacity makes it quite different from the 223AI, so that (over abundant) data is not the way to go fir starting loads.

I’ve been using a same lot of 222RM Brass, from a 500 qty case Made by Remington. I fire form it in the contender chamber. Then I adjust the FL DIE, using Bellm’s “headspace gospel for the contender”, to “partially neck size,” the neck only, just short of where the shoulder starts, which is not touched.
Stuffed to the top with Varget and 55 A-Max’s, it’ll punch a jagged hole all day long at 100 yds. Consistent velocities, cases smoothly lift out, when you say “Please.”

There has to be more varied data out there with powders that will be up there in FPS, but be kinder to the bbl. Thanks.


Well-Known Member
Dec 19, 2005
Good Ol' Oklahoma
If it were me, I'd use standard 222 Rem Mag data and work up from there. Depending on the increase in powder capacity of the 222RMAI, I might start at max loads for the std 222 RM and work up from there. Any good loading manual will have the standard 222 RM data. I did exactly this for the 30-30AI in a Contender.