I think you may have something a little off in your ballistics program to get the downrange energies that you quoted earlier. The 140 Grain load would have be travelling at 3445 FPS and that is faster than the IMR velocities for the 7MM RUM (3290) with 7828 powder.
In case you haven't noticed,even remington factory loads quote 3425fps for their 140gr factory load.And that factory load is quite mild.
The 7mmRUM will easily produce 3550fps to 3600fps using 140gr bullets.If you use tsx's or coated bullets such as the barnes xlc the velocitywill likelybe even higher.Even my 7mmstw's produce 3500fps with 140gr bulletswith less case capacity than my 7mmRUM.My own 7mmremmag would produce 3250fps with a 24" barrel.I have personally witnessed a 7mm remmag with a 28" barrel exceed 3350fps.
The numbers that Iam postingare actual chronographed velocitiesand not merely estimations or calculations.