The AR15 chambered in 458 socom with 11 rounds in semi-auto seems like a good option especially when it's not freezing. Now, when it comes to freezing temps and ice forming I don't trust the AR platform.
The owner of Buffalobore has used his 458 socom ammo on 2,000lb+ pound bison, AK/Yukon moose and brown bear and never recovered a bullet, complete pass through.
I do like the Ruger Guide Gun with 20" inch barrel chambered in 375 Ruger. My question is about that barrel length, should I look for a rifle with a longer barrel length for the added velocity or is a 20" inch barrel plenty?