Hey Bill,
You'll go down as a LEGEND around here if you nail the .223
1-7" twist.
Mag box dimensions that allow heavy for caliber bullets to fit/feed.
Throated to allow said bullets to touch lands at mag box lengths.
Most of us build them this way but wouldn't have to if you were on the ball.
Good luck man!
Sorry since 1-8 is by far our best selling twist for AR bbls they will be 1-8 with .223 Wylde chambers. I'm not sure on mag box length, I'd have to ask one of our engineers.
