Hi Ric,
I used to play the bullet game in all my 222's, 222 Mag and 223's - loaded something different in just about each one. They run from a 14" Bullberry Contender and custom 15" XP100, through several rifles and carbines with barrel lengths from 18"-26". I settled on the Speer 50 TNT across the board, adjusted loads and seating depth for each firearm to match it, and have been more than pleased in the killing fields. To me, shot placement should always be critical, so I have had no problems even on coyotes with the frangible pills. I save the 40's for my three 221 Fireballs now. Anyway, it works for me. YMMV
BTW, does RCR ring a bell with you?
Ladobe