The 222 traditionally has a 1:14 twist, as my rifle does, and it has a 22" barrel. Most deuce gurus will tell you that a 55 grainer is about all she'll stabilize. I shoot the flat base sierra 63 gr. semipoints well in it, and those noslers are trying to behave, but I can tell she's struggling with it. You have to really send them hot to increase the RPMs to ensure they stabilize. I have yet to get anything but a round hole in the target at 100 yds, but the groups are 1.5 MOA (and will get the occasional 2" or 3" flyer), instead of 1/2 MOA groups the 55s and 50's typically produce.

I have been trying some sierra 55 gr. gamekings, which mushroom instead of fragment. I got some decent groups today, and I may just stick with them for green field hunting. They are used in 220 swift and 22-250 chamberings quite a bit, but also expand and mushroom within the 222 and 223's more modest velocity ranges. It's always fun to taylor a round to a gun... and it's even more fun to do it with an obscure cartridge.