The moose ratio for 6.5x55 to .458 is probably 20000:1. The 6.5x55 was very popular for almost half a century and has proven it self to be more than capable of taking moose. Ammunition is also cheap and available everywhere. It has good accuracy and low recoil.Loxodrom it is good to have you posting. Why are the old 6.5 x 55 users afraid of the 458? NOISE? Over the years how many moose have been killed with a 6.5 x 55 vs a 458. I know that the old Swede may not be optimal for the task but it seems to me that it has been getting the job done for more years than most of us have been alive.