What is your idea of long range hunting? I've taken a few elk all the way out to 250 yards with a .270 with 150 grain bullets. While 250 yards isn't necessarily a long shot it might be outside the range of some hunters. Most of the elk I've ever taken have been inside 150 yards and most any legal centerfire cartridge will work on elk at that range.
If you are talking about hunting elk at ranges beyond 400 yards then you better know what you are doing. I've seen the 700 yard shots on bull elk in videos before, and thought man I could never pull off a shot like that. I don't want to pull off a shot like that anyway, I just like to be in closer when I squeeze the trigger.
If I get your signature line correct you, own a 7mm Rem Mag and this rifle will do exactly what you want it to do. I'd use 160 grain and up bullets for any elk hunting that you may do. You should be able to take any elk with good shot placement out to 400 yards without too much work.
Most of the guys I hunt with use the .30-06 and they consistently take their elk every year. Yes elk are big but they are not bullet proof, and I've never seen a magnum rifle put them down any faster than a .30-06 does. Dead is dead and very rarely have I seen a properly placed bullet fail to kill an animal with one shot.