The 300 WBY wouldn't be my first choice in a factory form for a long range starter gun, it's rare to get true long range accuracy, not that it doesn't happen but the throating has to be perfect with the amount of free bore they have, the mag box restriction is painful too. MOA accuracy frankly isn't going to cut it, on paper it looks good enough but that means if YOU have to be a tenth MOA shooter to keep an MOA gun good, and that an MOA gun at 100 which is frankly easy to achieve but to keep an MOA gun MOA at long range not an easy task!!
Remember if your an MOA shooter with and MOA gun that's 2 MOA of possible error so at 800 yards your all over the side of one without wind or any other factors!!