I've run 3031 with 55's in several '250's. One was a 26", the others 22".
The last one clocked at 3,580 "something" with 35.5 grs 3031 (Sierra 55 BTHP) in a 22" barrel and shot great.
Had good luck with RL15 and the 52 A-Max in a 24" that clocked 3,620-40, but I don't have the exact charge in front of me.
The 3031 load shot better.
