I just started loading for my 300 ultra mag and using nosler 125 gr blstp with 92.5gr H4831 I want to load some of hornady 110 v-max for varmits and see what that can do and if I can get it faster yet the 125 seems to match to the gun perfectly I get half inch 3 shot groups at 100yds anybody got any info would like to hear it thanks.

Try using "Retumbo" powder. It might squeez out some more FPS. Hodgdon claims it made this powder for the "Ultra" mags.

You could try the .308 90 grain FMJ from The Old Western Scrouger, if you're just looking for a peak velocity.

Mike