Got your address, and the dope is on the way. I did it out to 1K yards. Note the difference in drop, velocity, and wind drift. Energy at that range is about a tie, but the .260 will pull away as the distance increases.

I don't know if you can load 175g SMK's for an AR-10. Someone else here will. If 168's happen to be the max, the difference will be much more dramatic.