If I had to buy a magnum??
If I were to buy a magnum for Deer it would be a 7mm Rem mag. The main reason is that for a magnum the recoil is light for a magnum and it is the most popular of all magnums. If I was buying this magnum for Elk it would be in 338 Win mag. The 338 is far superior to 7mm on an animal with the size of an Elk. I think the 7mm Rem mag is in the top 10 of cartridges sold and availability for buying factory ammo is great. Same for finding them onsale at a discount. For the reloader other than the belted case reloading should be easy, with no shortage of great bullets available in 7mm to choose from. This also goes for your choice of rifles, all the manufactures chamber the 7mm Rem mag in their rifles.