Buffalo River Shooting Rest | Buffalo River | ArdMoor
I have used one of these (borrowed from a friend) in the past to do what you're asking. It worked surprisingly well and if I had one myself I'd probably use it when setting up all rifles and scopes.
I didn't shoot off the rest, I shot as normal, prone off a bipod and rear bag. I then put the rifle in the rest, adjusted it until the crosshair was over the aiming point, then adjusted the scope until the crosshair was now over the hole.
I then shot the rifle again as normal off the rest and it was pretty much dead on.
Some things to bear in mind are that you still need to bore sight the rifle first to get it close to the target and then I'd want to shoot a couple of groups to confirm the average poi.
With ammo prices for copper bullets this rest could easily pay for itself in a couple of sessions.