Top load with Big game worked for me.
I got the very best barrel life with AA2700, one of the coolest burning powders on the market....if you can find any. I got the shortest barrel life with R#15, 4064, and Varget. P. dog towns and chuck shooting will teach you a thing or two on what powders eat up a barrel.
AA2700 is the same powder as H414 or Win 760., in case you didn't know.