For the Scenar I was using 44.8gr Varget. Unfortunately my rifle (custom 308 liked the SMK's better for accuracy. 1/4 MOA wasn't a problem at 100yds but at 300yds they were opening up to 1/3 MOA at best while the SMK's held 1/4 MOA to 300yds. My velocites were approaching 2900fps with a 25" Shilen barrel. Please Start low and work up.
They were not the silver. I was using Rem 9 1/2 and CCI-BR2 primers (both worked well). The twist on the barrel was 1:10. Factory barrels generally give slower MV's.