this isn't really incredible news based on all the posts, but using tips from Bob CZ550 I just finished load testing on my CZ550 20.5" barrel, with a suppressor, using R17
250accubound 1/4-3/8" groups, 2670fps
286 part 1/2" groups 2500fps, 1" group w hot load 2600fps
250ttsx 3/4" group 2635fps
I can get more speed, but shooting thru the same hole is cool
