Did the OP, oldmate, ever decide on a load?
The 154-gr Hornady RN are great bullets, but discontinued. I am hoarding my last 100 of them.
There are so many good 150-gr and 160-gr bullets that you can work up loads which shoot to the same trajectory out to 200 yards, but have different construction, from the 162-gr SST, to the 160-gr Sierra SPBT GK, the tougher HPBT GK, the Speer Hot Cor and Grand Slam, and Nosler Partition. The flat base Sierra Pro Hunter, Hornady Interlock, and Speer Hot Cor are all you need to shoot most anything with a 7x57. Eleanor and Jack O'Connor shot a boatload of big game in Africa with the 7x57 loaded to 2,600 fps with a Speer 160-gr.