Both my Rem700 BDL, and that of a friends - like 21.0 of IMR-4198 with CCI 400's at regular old "book COL", 2.130" or whatever it is. The key is the primer, but we're seeing speeds of 3,300 or just slightly better in mine, and as much as 3,385 fps with the same 21.0 grain load in his with the 40gr Hornady V-MAX's.
I need to re-test 21.0 and 21.1 again in mine, but in his - at 21.1 we were actually seeing the group fall apart a little and velocity was degrading as well. So in his, 21.0 is definitely 'the one'. Do a ballistic calculator run on a 50 weight bullet in 222 going 3,000 or at most lets say 3,100, versus a 40 doing 3,385! I'll take these great, long, boat tail 40 V-MAX's any day. I haven't shot anything yet that they haven't anchored perfectly. But the 222 loves them all I think, and most every powder you would ever want to try in it as well! So IMR-4198, or H4198, or BL-C2, Reloader 7, possibly even 10x, Benchmark, H335, ...etc., with 40's, or with 50 Blitz, 50 TNT, 50 Blitzkings or V-MAX's, 52HPBT's, 52 Bergers, whatever. I agree with what Roninflag said - the 222 rem is:
"the easiest most forgiving cartridge to load for hands down."