Hard to answer. You need to know the diameter of the bell outside the 50mm lens and the diameter of the scope tube.
Using the information above a 30mm low mount is centered .990 above the receiver, medium is 1.09, and high is 1.19.
Measure the diameter of the front bell and divide it by 2, then see which one will have the clearance you need.
For a 1" diameter scope mount subtract .090 from the above figures.