The .308 I really don't see as a long lasting cartridge. Kinda like the WSM's a RSSM's, it'll die a slow death. I wouldn't expect ammo to be widely availble for it either, unless of course it actually catches on. The .450 Marlin it's super avialable either but more so than the previous. If you're to be reloading it's a whole different story though. Personally, iId opt for either the .35 Rem or 45-70 chambered XLRs. Ammo is plenty available and both provide planty of knock down oomph for anything on this continent. Both have been very good cartridges for a long time and the game animals haven't gotten any tougher hides so that the latest ad greatest magnums are required.