Does a 6.5x55 with 140s allow you to practice more and be noticably more accurate than an 06 with 165/180gr?

When you take that suboptimal shot without pausing to consider angle properly with limited daylight next to thick cover when tired, frustrated and desperate which will you rather have had in your shoulder.

I dont hunt elk - I do hunt large smart deer in wilderness. I imagine perfect scenarios but I get realism and carry my 7-08. I can't think of a time Ive wished I had my 243 in such situations even thoughI shoot it fractionally better.