On the topic of the original post, i shot 8 animals last year with the 140 elite hunters out of a 6.5 cm in Colorado and WY. All but one was a one shot drop and the only reason I put a second into that big mule deer at 450 was because he was pointed towards the private. If I didn't have elk on my plate I wouldn't even bother with another setup.
Load development was so boring it's not even worth noting. Just don't try to reinvent the wheel. I'm using Lapua brass, H4350, CCIBR4 primers and those bullets. Took about 60 shots from start of load development/ barrel break in, to validated to 600.