Hornady's 8th Edition lists 23.2 grains of H335 as maximum for 3100 fps from a 26" 1/12 twist Winchester bolt rifle using WSR primers in Win cases. This is very conservative in my opinion. Overall recommended length is 2.250" for the 55 V-Max. I've shot the same loads with the V-Max 55 grain as with Hornady's 55 fmj's in my AR's using Hodgdon's maximum recommended load data for H335 with no pressure issues and velocities in the 3150 range in a
20" 1/7 and 1/9 barrel. Do work up your loads.