7mm rem mag, it will do anything the 300wm will but with less recoil & powder. 300wm makes it's hay with 180-200gr bullets and these really aren't required for the likes of deer. Though like stated if you already have a 45-70 and 270win you got all you need for your stated usage/requirements.
TGH, the 300wm and 3006(ect) use the EXACT same bullet all .308 caliber based cartridges.
