Remington still uses a 12T in their 223's..... if that's important to you? Most everyone else has climbed on the "heavier must be better" bus and gone with faster twist barrels. I have an older CZ 527 with a slow twist,and will never part with it. Loading cast in a slow twist isn't going to be an "easy button" comparitively but it is entirely doable. My '19 ADL shoots 55g with starting JB loads.... and in at least one loading am darn near book "max". But once velocity gets up that far,I'll grab one of the 22-250's.... just sayin. I don't really "like" punching holes in paper or,sitting at a bench..... and have ALL the bells N whistles WRT to BR. Would rather be varmint blasting..... with highly frangible CB's running wide open. Being old and lazy,prefer skinny barrels. Being too dumb to come in out of the rain,prefer stainless and plastic bolt guns..... although cerakote is growing on me. Good luck with your project.