Here's a few things I've found to work behind 50-55gr Nosler .224 bullets in the 5.56 or Wylde chambers. Hornady bullets typically have greater bearing surface at the same weight, so reduce loads, and work up accroding
28.5gr BLC-2
27.5gr H335
27.5gr TAC.
Most any brass except Federal.
CCI-450 or, when you can get them, S&B small rifle primers.
OAL, GI magazine length.
