I finally decided to reload for it. my Hornady manual has a listing for the 223 rem. and one for 223 rem service rifle (ar-15). the ar data Has a 68 gr and a 75 gr. bullet listed, now if I want to reload a lighter bullet will it shot them alright? the service rifle data is for a 1 in 9 twist witch is what my rifle is. the other data is for a 1 in 12 twist.

youll be fin with a lighter bullet.....my ar-15 is a 1:7 barrel and it shoots 55 grain noslers good.

I shoot 52gr and 55gr bullets out of my 1:9" AR with great accuracy.

I'd go with the 55 gr bullets. I haven't tried to buy any in awhile but a few years back you could buy bulk 55 gr bullets FMJ or SP mighty cheap. Hopefully you still can and the .223's love these bullets.