I have a 6.5x55 built on a Sako with a Douglas barrel. Here is my load ( NO B.S. ) 500 meters 2 1/4 to 2 1/2 inch groups all day long.
R-22 powder ( 47 Grains )
Lapua Brass ( trimmed to 2.150 in. )
Lapua 108 gr. Scenar Bullet
Federal 210 Primer
O/A Length 3.065 in.
GOOD LUCK
Dan