It took me around an hour to dial in my 300 win mag a couple years ago. There is no doubt in my mind if I shoot a giant bodied bull with my 300 that it’s going to hit the ground hard after pulling the trigger with one shell.
The fact that you started this post means that you are unsure and questioning your confidence in your 6.5 on a species that can take a bit of punishment before falling.
Wet weather is a reality in Alaska and can wash blood within minutes after a shot if raining. You may feel incredibly bad if a bull you shoot with a 6.5 runs a ways, blood disappears, and you can’t find him in a 10 to 15’ tall alder jungle. Tall, thick tangled alder are also a reality to deal with in most Alaska moose units.
I wouldn’t exactly say a 6.5 would be my weapon of choice to anchor a bull in his tracks. You definitely don’t want to try shooting him through the shoulders trying to anchor him.
I have a Colo moose tag and if I end up rifle hunting I know which rifle I will grab…no questions asked!