bsa: The velocity figures were not mine. They were from an article by Bob Hagel on the OKH cartridges:
".....Ralph Avery,who did a lot of experimenting with the 334 OKH cartridge,had several chronograph checks made by Joyce Hornady. I (Hagel) have copies of these reports which show velocity to be very good using H-4831 powder....A charge of of 80 grains of this powder behind the Barnes 250 gr bullet,with an over all cartridge length of 3.75 inches,gave an average muzzle velocity of 2895....." Bob Hagel; "OKH Cartridges"; Guns, Loads,& Hunting Tips.
I understated in lifting the info.
