Actually, Jack O'Connor agreed that the .280 was a better all round cartridge than the .270...In his later years, Jim Carmichel went to him and was discussing a custom rifle he was having built...Jim had already decided on a .280, but so he wouldn't hurt Jack's feelings, he told him he was getting a .270...Seems Jack jumped up and said "Don't do it, go with a .280, it's a better round"...

Jack liked the .270 simply because it shot a little flatter than the '06 and it kicked a little less...He felt that the average rifleman at the time could handle the reduced recoil a bit better...