I have experimented quite a bit with mine using 4198, AA2200, AA1680, and Lilgun (CZ 527 Varmint). It really likes AA2200 and a 25gr Berger Match Varmint. The same powder also works well for the 20 & 25gr Vmax. I have the velocity numbers around somewhere, I will see if I can dig those up. For me, the 2200 has been the fastest. As always, use this data with caution and double check with a reloading manual before use. Reduce and work up.
cartridge, powder, primer, bullet weight/type, powder charge, OAL
17H Hornady A1680 Rem 7.5 20 Nos VG 10.4 1.720
17H Hornady A1680 Rem 7.5 25 vmax 9.2 1.720
17H Hornady A1680 Rem 7.5 20 zmax 10.5 1.720
17H Hornady A2200 Rem 7.5 25 BMV 12.0 1.715
17H Hornady A2200 Rem 7.5 25 BMV 12.1 1.715
17H Hornady A2200 Rem 7.5 25 BMV 12.2 1.715
17H Hornady A2200 Rem 7.5 25 BMV 12.3 1.715
17H Hornady A2200 Rem 7.5 25 BMV 12.4 1.715
17H Hornady A1680 Rem 7.5 25 vmax 9.4 1.711