Tape, I think your "one-hole" statement and your sig are throwing people off. I don't think you're explaining what you mean very clearly.
Obviously there are some rifles that will shoot one-hole groups out to pretty impressive distances off a very solid rest, but most rifles will not, no matter what vice or bench you're using. Mechanical accuracy is not infinite, and is far, FAR from equal between all weapons.
Please do explain your ideas in more detail so we can stop speculating about what you meant to say.