Best rifle caliber for western hunting?

[Old3Toe]

There ain't no way, under any circumstances, that I'd even consider a new, unfamiliar, and unproven gun/scope/caliber for such an endeavor. That is to say you cannot buy the level of familiarity, history of success, and confidence that you have now with your 270. Also, you didn't specify what your whitetail bullet/load is, but there's a high probability that it's fully adequate and capable for elk as-is.

PS. I'm not a 270 user. My preferred elk and deer cartridge is the 7x57... which iirc is was what Jack's wife Eleanore O'Conner used!

 

[FCCDerek]

Personally, I use a 280AI for my western rifle, since I live in the west. It will handily drop any critter walking the North American continent. Doesn't mean your 270 would leave you undergunned though. 270 is just fine. I'd shoot a 140 or 150 grain bullet for elk, just my opinion. I'm not sure what your rifle twist is, you may not be able to stabilize the 150's if it's an older one.

 

[cjallen4]

I find it very interesting the 7 rem mag has only been mentioned a very short few times. it is similar to the .270 but probably the #1 elk killing rifle in the US. just my 2 cents