vv powder will yield (in most cases) top velocity (if going for that)? almost everything else gets about 50-150fps slower and probably more barrel life (100 series included). i'm hoping hd, match and grand will fill the spots of those "can't get or limited run" powders. back to the hd..........not sure what velocities and fill rate it'll have, but seems to be in the same realm (according to published data) as 1's with comparable burn rate(s) (overbore and heavy for caliber type). when rl33 came out it was designed for 338lm (supposedly)? with several unproven guns that need load developments i have (243win, 6.5prc, 264wm, 7saum, 300wm & 338lm), i hope it works great for cartridge.