I am trying a Leupold 3x9 on My 99F (it had an old Tasco on it when I bought it). It has swing-away mounts which worked fine for the Tasco, but the Leupy barely has any clearance between the barrel and the bell. I removed the rear sight leaf already. Will I be OK with a paper width's space between the scope and barrel or will it crack the scope? Is it possible to shim under the mounts to give extra clearance assuming the screws are long enough? First time I have run across this problem.