When assessing various chambers for elk and shooting distances you could assess PBR and cartridge use. The first thing I would assess is all up rifle weight as roaming high altitude terrain for several days does make a difference, especially with greater age. When looking at various popular chambers and PBR with modern powders, bullets and velocities the 270 Win with 140 gr load is about 310 yards, the 30-06 with 165 gr. load is about 295 yards, the 308 Win with 165 gr. loads is about 276 yards, the 7-08 Rem with 150 gr load is about 288 yards. All will kill an elk quite satisfactorily. Again most elk are shot inside 200 yards and close to 90% no more than 300 yards. All the previous mentioned chambers easily reach 400 yards with aplomb and deliver more than sufficient energy at that distance with right bullet choices and the right placement. For me the lighter carrying the better. But that’s just me. Some would consider only magnum use and that’s fine as well. The 7mm Rem Mag is a great elk cartridge, but in reality at the distances most elk are killed it doesn’t perform any better than the aforementioned chambers.