I have to think a Cooper in the Fireball would be the ultimate no excuses rifle - if you miss, you can't blame the gun
There is in fact one on Gunbroker right now.
The XP-100R were frequently very accurate - this one I had in .22-250, and wish I'd kept it:
I now have one in 7mm BR. I won't say it's bubba'd...maybe thibadeaux'd....