I will add to MD post that O’Connor often stated he did not see much difference in killing between 7x57, 270, 30-06, the various 300 and 338 mags on game (including plains game) up to Elk. It was not always this way in his writing
You can clearly see in his writings that in early days he liked to take a 270 for sheep/deer and 30-06 with heavier bullets for Bigger game like bear and Moose. After he killed a bunch of bigger animals with the 270 cause he ran into a caribou, moose or grizzly sheep hunting figured out it worked as good as the 06 on bigger animals and started using it more as preferred the flat trajectory. When the 300 wby, 338 win, 7 rem Mag came out, he used those and did not see much of a difference taking game just more recoil and heavier guns.
For middle period (and most prolific) of career settled on the 270 Win with 130 and 150 Nosers for most hunting especially a lot of international hunts, though still used other stuff. When hunting really big or dangerous game he went to something bigger but that was something bigger than something like an Elk, Kudu, or Zebra where he found the 270 will shoot through and kill fine. So as with the Boddington thread it wasn’t “270 for everything” from the beginning. In using the 270, he found it worked well with good bullet construction despite some early concerns with light bullets
I expect like a lot of older hunters he was less worried with theoretical long range situations and more worried about pracitcal things like recoil as got older and used the 7x57 more
Lou
