The exert below has been copied from Sierra reloading data for the 7mm Rem Mag and is a fair reflection on this venerable cartridge. I have also read somewhere that the 7mm Rem Mag is near the top for sales of reloading dies.

Those that espouse that 7mm cartridges based on the 08 and 06 cases come close to or equal the 7mm Rem Mag have little idea of ballistics and are talking bullshit. With the correct powders the Rem Mag can be loaded just like any other belted magnum and will always have a good edge over any smaller capacity case.

From Sierra loading data;
The 7mm Remington Magnum is, first and foremost, a hunting cartridge
and has been used to take virtually every big game species in North America,
including big bears. Realistically, it is probably at its best when used in long range,
open country hunting typical of western big game territory. While its primary
use is in the hunting fields, the cartridge’s flat trajectory and inherent
accuracy has attracted the interest of competitive shooters as well. Eight years
after its introduction, it was used in conjunction with Sierra’s 168 grain
Match King to win the prestigious 1000 yard Wimbledon match at Camp Perry.
At this writing, the U.S. Secret Service counter-sniper teams are armed with
custom-built 7mm Remington Magnums. Considering their stringent requirements
for 1000 yard accuracy, this is quite a recommendation for the versatile
7mm Remington Magnum.