Having a similar debate as I drew my tag for Pronghorn this year. I have several rifles that fit the hunt. My Rem700, 6mm Remington has killed a few hundred animals, including elk and moose, and is amazingly accurate. My Sako85 Finnlight, 270WSM is fast, accurate, and light on the shoulder. The Sako85, 270Win is the most accurate rifle in my locker, a bit heavier than the Finnlight, but easier to shoot quickly. The Sako85, 7mmRM is the best long range hunting rig in my locker but a much heavier rifle. I also have a flyweight 35Whelen that is also amazingly accurate and a pleasure to carry and very capable of reaching out to 500 metres.
Weeding this list down keeps bringing me to the 270Win as I can shoot accurately, the Swarovski BRH is well calibrated with the ballistics data, I trust my skills to 200 metres offhand and to 700 metres from a bipod. Considering where I will be hunting and shots likely to be around 300 metres, I am going with my 270. All that practically aside, it would be very cool to carry the 35 for this hunt.