CptCurl- now THAT's a co-incidence- just shows we're on the same page with top-end loads in the 6.3.
: My notes indicate I dropped my charge to 67.0gr. BLC2, & using '06 brass(probably WW) and fired froma cold barrel, gave me 2,550, virtually identical to your results.
: I found the '06 brass to reduce pressure considerably, yet deliver consistantly good velocities and accuracy.
: John Tylor's notes in "African Rifles and Cartridges" stated that the 9.3X62 ws the most popular medium bore at the time of writing. The ballistics at that time were a 285gr. Solid or Soft, driven by 54gr. of smokeless powder for a velocity of 2,175fps, FPE of 3,000 and KO of 32.4 - all this produced 16 1/2 tons or 36,000PSI. He also noted the Germans upped the velocity and pressure to 2,400fps with those same 285gr. bullets. As an aside, I worked with some loads using W760 powder and with 63.5gr., drove the Norma 286gr. at 2,332fps, duplicating modern factory ammo, but at very low pressure, KO34.9. To meet or exceeed this Knock Out Value, marginally, I found the 270gr. Speer bullet runs 2,489fps using 60gr. IMR4064 which produces 35.1 KO points. Of course, the BLC2 load is slightly improved, but probably produces no visible increase in effect on game animals.