Pursuant to Range Rats excellent advice above, please note that provided you stick to 55 - 62 gr standard milsurp, there is no leade issue, especially given the Handi's tendency to a slightly longer 223 chamber. In any event, the longer 5.56 bullets - tracer, non-tox, and armor piercing in the main, will not stabilize in the Handi's later 1:9 twist and most certainly not in the earlier 1:12 twist. So, any 5.56 that would accurately shoot from a Handi barrel will fit comfortably in the 223 Handi chamber.