Although they are on the hairy edge with a 1:9 I have had success with Hornady 55gr SP SX. The jacket is so thin that with a 1:9 at 223 velocities they could spin the jacket right off. Mine hold together and are positively explosive.
I've been trying 55gr SPSX in a 223 Savage I just got. While working up a load on the weekend I noticed that some of the groups at the higher end (26.5-27gr Varget) only had 3 holes on paper rather than 5, I was suspecting the bullets were coming apart as I couldn't see accuracy going from MOA to minute of barn, but I wasn't sure. I guess my suspicions are confirmed. I always thought SPSX were good to go until you moved up into 22-250 territory, but maybe the 1:9 has an effect.


















































