In Quickload, if I optimize best powder for that cartridge at 65 kpsi with the same 162 gr bullet for velocity with (16) different 7mm cartridges, the point of diminishing returns is around the 280AI and 7mmRemMag point.
After that, it is a lot more powder for small velocity increase.
7mm T/CU, 7-30 Waters, 7mm BR, 7mm IHMSA, 7mm-08, 7mm-08 Ackley Improved, 7x57mm, 7x57mm Ackley Improved, 284 Win, 280 Rem, 7mm Rem short action ultra mag, 280 Rem Ackley Improved, 7mmRemMag, 7mm Ultra mag, 7mm Weath Mag, 7mm STW
But personally, even though I have a lot of reamers, I build more rifles in 6.5-06 and 7mmRemMag.