Hello eale27. There is a reason for the overhanging base. There is a small ledge that hangs over the action with a large set screw that keeps the base from moving forward under recoil. this takes the load off the 2 screws that hold the base. I fabricated a new stud and relocated the stud in the forward CZ ring to fit tightly into the slot in the base. All in all the 16mm CZ rings worked great on the 2.5x32 scope that I mounted. This allows for quick and easy "on-off" scope and iron site swapping, as needed. Field tests with the scope to follow.

Here is a picture of the 416 Rigby cartridge next to a 416 Van Horn cartridge. With modern powders the 416 Van Horn can equal original 416 Rigby performance.

And a picture of a target using the iron sites. This is a fun "puppy" load for practice.

And finally a picture of the mounted scope showing the overhang base. If you look close you can see the large set screw.

http://www.buckstix.com/buckpics/RIGBY-VAN-HORN.jpg

http://www.buckstix.com/buckpics/abe-targ.jpg

http://www.buckstix.com/buckpics/abe-scope-0.jpg