I have owned, handloaded and shot both the 7MM STW and RUM.I have settled on the STW.It will do anything the RUM will do with a 140 grain bullet, which is what I shoot.
My groups run 1/2 to 1 inch @ 3550 fps with the Nosler 140 bal tip.
Remington is without a doubt one of the most accurate rifles in any caliber that you can buy right off the shelf.
In my Hart barreled 7STW I have no trouble keeping 5 shot groups under a half inch with heavy loads and hunting bullets.
While experimenting with RE25 and 140gr B-Tips I was also able to achieve velocities in excess of 3,500 ft/sec. However, this was definately a HOT load and I normally shoot them between 3,300-3,400 ft/sec.