RE: 6.5x55 vs. 7x57
The lack of velocity that the 6.5 X 55 seems to give up to the 7 X 55 in the same bullet weights isn't the whole story. The longer projectile of the smaller diameter 6.5 in the same weight as the 7 X 57 gives superb penetration.....of course so does the 7 X 57.
They are both superb.