I did a lot of work with H4831 in my 270 WCF BRNO ZKK 600 (had a 23.50" barrel) both with 140 grain HORNADY INTERLOCK and 150 grain HORNADY INTERLOCK. I am in mid-process of experimenting with Nosler Partition 150 grain and the older perhaps more desirable Nosler Partition Gold that have the "partition" further forward to give greater retained weight.
Anyway FWIW here are results with H4831 and the Hornady 140 grain Interlock Boattail:
55.4 gns = 2856 fps
56.0 gns = 2867 fps
56.4 gns = 2892 fps
56.8 gns = 2905 fps
All FIVE SHOT strings and tested ten feet off the muzzle, November 2007, 53 degrees Fahrenheit temperature.
And here the one loading that I did with H4831 and the 150 grain Hornady Interlock Flat Base:
55.0 gns 2809 fps WITH CCI LARGE RIFLE PRIMER
55.0 gns 2803 fps WITH REMINGTON 9 1/2 PRIMER
Velocities over five rounds all within 30 fps spread with CCI - 2801 fps to 2831 fps. With Remington 9 1/2 the extreme spread was 116 fps! Use CCI for best results!
I hope this helps at least give an idea of velocity that I achieved with my 270 WCF. If you want heavier bullet information try the American
http://www.accuratereloading.com site that has a good lot of helpful members with strong opinions!
And although these loads were OK in my rifle they may be unsafe in other rifles...including yours! So these figures are given as information only not as recommendations!