The "solution" for scope mounting on a M1903 is a Griffin & Howe side mount, although it does require some wood work. Folks were not into preparing their rifles for scope mounting back in the first part of the 1900s, so every claw mount was almost unique.

As for the reloading, I have been reloading the 6.5x54mm since 1976 with first 37 to 38 grains of Norma 203 with 140 grain and 156 grain class bullets from Norma, Speer, and RWS. When N203 began to undergo changes I moved to Norma 204 at 39 to 40 grains with Hornaday 140 and 160 RNs, Speer 140 (.263) RWS H-mantles, and Norma 156 gr. Vulkan and Oryx. Velocities amongst all these loads vary from a low of 270 fps to 2490 fps. The RWS and other heavy bullets run 2360 fps to 2375 fps, best consistency of all.

Firearms used = M1903 carbine (2), MCA carbine, SBS-96 carbine