Gotta go with the .300. i have the .300 weatherby mag ultralite. This gun can load up for elk and even moose as well as down for deer. Some bear of the tan to brown color concern me though. Think the 375 would come along on that hunt if I ever get to go. The .300 win mag is similar and a bit more cost effective. I would finish with spending as much on the optics as the gun as they seem more important in the long run.