If you feel like the cci 450 is not hot enough, then the Tula small rifle magnum primer will end all doubts as it is hotter than the 450.

I have played with the small and large primers in the 6 XC. The 308 palma brass with the small primer is really tough compared to the norma large rifle. I shot the 107s at an accuracy node of 3270 fps in a long barrel