My comments are not for you. You have made up your mind and that is fine. I am sure you will do fine and lots of bull elk have fallen to the 250 thor. Maybe the extra 50 gr is an overkill. My comments are simply giving my opinion for those who still are trying to decide

Everyone has their own comfort level, and in most cases mine for elk starts at 300 gr. However:

250 thor or 350 gr powerbelt: Thor hands down.

But, accuracy being equal:

250 gr thor or 350 gr FPB: FPB

250 gr thor or 300 gr thor: 300 gr thor

Since they are the same price, if the 300 shoots as accurately, I can't think of a reason I would not use the 300. And the difference in drop out to 150 yards is not significant.

But that what my comfort level tells ME. Your results may vary.