Interesting you posted this, as I`m thinking of the same problem, with the same bullets you mentioned. I`m leaning to the 175 Sierra Pro-Hunters...I`ve used them a lot on deer here, and took that bullet and cartridge to Africa my first trip. At 2800fps using 4320 the load is very accurate, and killed everything I pointed the gun at. I also killed my last Elk with my 8mm06 AI using that bullet. Broke offside shoulder and lodged aginst the hide.
I`ve not used Weldcore, but my second choice would be either a 200 Accubond or Partition.
Agree on the 170 SST, just don`t know on Elk, but have killed water jugs to 600. Very accurate.
Do you have the 700 Classic? or something else?