200 lrx handloaded to 2800fps will serve you well. I have taken a moose with the 200 lrx out of an '06 at 468yds. MV was only 2600 and change. Bullet hit the thick bone at the bottom of the shoulder blade....sheared that bone right off, carried straight through and sheared off the offside bone in the same place as well....everything in between....jello. Barnes reccomends 1600fps impact velocity for the 200 LRX, so if we say 1700fps to give it some wiggle room, your 300 pushing it 2800 fps should give you an effective range out to 700 yds give or take. The heaviest bone will not be a problem....even at 700 yds. Good luck!
Chris
Chris