I like weatherby calibers, the mk5 is stronger than the 700, but limited to a new trigger, truing, and a few stocks, I would most likely buy a weatherby but it would be the accumark, sometimes the ultra lights don't shoot that great and heat up fast because of the little pencil barrels. If you use factory ammo both the weatherby and the rum will cost you 60-70$ a box for accubond or partition loads, if you reload wby takes the advantage due to better brass. Also with factory loads they both run neck an neck velocity wise, reloading gives the rum about 100-125fps more with full on loads, but they are still about equal if you load the rum where you can get more than 2 or 3 loads per case.