Dusty Stevens
Shiner
I use the RCBS small base dies for AR15 and AR10. Only thing is that even with vibratory cleaning until the brass shines, 223/556 brass will tear up those dies after a while. Keep them clean and polished with IOSSO or JB.
I think to use those rcbs dies you need a sho nuff match chamber. My cle chamber works great and my dads wylde does too. The colt match hbar .223 i have is way too big for that die. I havent even tried just a nato chamber fired brass in it