I load for 5 different 223 barrels(3 AR, 2 bolt guns)and a 20p. No competition, varmits,prairie dog and load development. I use one rcbs .223 rem standard FL sizing die. Ring is locked, designated shell holder. It sizes brass to minimum SAAMI on a Lyman ammo checker(low step). That brass fits all the barrels even in the winter. I have a witness mark on the press/die ring I make sure to check. This is for using range brass. For brass dedicated to a specific rifle, I use a shim ring to put lift the die about 0.002. But really it hasn't made any difference accuracy wise, and I haven't had case head separation. So I wonder why I bother. I do anneal. Most new brass and ammo is short(lower) in the ammo checker. KISS seems to fit me best.