As a newbie to Idaho 25 years ago I carried a .30-06 elk hunting since it seemed like a logical choice. Saw a nice elk out in an open area but it was 350-400-450-500 yards away? This was pre-LRF days and I hadn't gotten used to range estimation in the mountains. Anyway, just a bit too far for me to feel comfortable shooting with the rig in hand.
So I bought a 7mm RM since it was and is a very flat shooting round. I loaded it with 150 grain Nosler Partitions and Bob Hagel powder charges, then practiced with it all year and got to where from prone I could make good consistent hits out to 500 yards.
When elk season rolled around next year I was ready for come what may!
So, of course, a nice elk stepped out of the forest about 30 yards in front of me. The 7mm still worked. Killed a nice deer with it that year as well, it was maybe 45 yards away.
Went back to a .30-06 and had a string of one shot kills for the next 10 years in a row.