The 243 with a 105 is a completely different animal than a 243 with pretty much anything else lessor in BC.
I've been very impressed with the results of a 105 in mountain terrain with shots over 300yds, and do not/would not hesitate to take any shot at even the biggest bodied buck. Not far by any stretch of the imagination, but far enough that a poorly placed shot can lead to a very long and exhausting recovery process. I don't have a yardage limit, more of a common sense limit given the wind and terrain and what the consequences will be.
