243 with a high quality projectile. muzzle brake or a suppressor will make it real soft shooting.
+1. Also consider a semi-auto. My Browning BAR semi-auto in .243 has noticeably less felt recoil than my ,243 BLR levergun shooting the exact same load.
That has got to be sweet, If I find one of those or a 25-06 it is coming home with me.