6x47L, efficient design, brass is the best available, lasts seemingly forever even with warm loads, capable of 3200 fps in a longer barrel with 105's. Over 30 reloads for me during a decade now.
The only other cartridge I'm tempted to try is 6mmDasher. Same attributes as x47 but with 32 grains of powder so 105's around 3000 fps in a longer barrel. Long range benchrest records have been set with this cartridge.
Not to be a mean or pick a fight but 243wssm was extremely disappointing to me in more than a few ways.