Assuming that Zeiss's measurements are correct and the outside diameter of the tube at the objective lens is exactly 56mm it would make the measurement to the center of the scope at the objective lens 1.10236".
The measurement to the center of the front ring 30mm medium DNZ mounts is 1.105".
This would give you a clearance of .00264" at the receiver. Less than the thickness of a piece of notebook paper.
If you include the step down from the receiver to the barrel and the taper of the barrel this should give you a gap of less than 1/8 of an inch. This measurement would of course depend on the position of the scope, front to back, for eye relief but it would clear with a very small gap.[/QUOTE
Gun enthusiast/mathematics grand master