I have loaded both mild and hot loads of 140 gr Sierra GK for two rifles, my current Tikka T3 and Mauser 98 based sporter. My powder of choice for 140 gr and up is RL22. For 120 grainers I use IMR4320. I don't see advantage of high velocities in this caliber. The beauty of military spec (fast twist rate) 6.5x55 is that is is very effective at lower muzzle speeds (2200-2500 fps) and very long distance due to large sectional density of 140-160 gr bullets. Besides noncorrosive primer, the reason behind longevity of military Swede barrels was low velocity bullet. Plus 6.5x55 brass does not tolerate high pressures.
