Re: .300 rum
My 300 RUM does spectacular at 1000 yards. I have a fairly mild load built for it that prints nearly 3/8 moa at 100 yards. I have found the best accuracy with the Berger 210gr Hunting VLD. It is loaded to produce 2800fps, which is where I have found the accuracy node with all the 210-220gr bullets I have shot through it (only 220 Sierra Matchking and the aforementioned Berger). At 1000 yards I dial 8.2mils and still maintain 1582fps and 1167ft-lbs of energy (almost enough energy to knock the frame over that my steel plate hangs from).
I personally shoot no more then 3 rounds at ANY given time. I have heard the 300 RUM is a barrel smoker, and plan to take it easy. My platform is a Remington Model 700P, with the factory 1in10 twist 26" barrel. The only thing I have done to it is add the muzzlebrake, which was a necessity as the scope was touching my forehead during recoil above 2700fps. I didnt want the half moon above my right eye so I had the brake installed, and do not regret it one bit. Recoil is much similar to my 308 now.
(P.S. it is for sale in the for sale section here. I have decided to rebarrel my 308 to 260 and my 223 to 223AI with an 8 twist)
Matt