Mount or sight problem

[fangsnatcher]

hi,

I've mounted my new nikko stirling 4-12 x 50 sight and have got a rough zero. the problem is at 50 meters my fall of shot is generally (excluding flyers) one mildot right of the target and i already am at the limit of my adjustment. the same is true with elevation with the scope as low as it will go. ive remounted the scope twice and its still the same. the mount is a nikko stirling one but the two halves are vertically orientated, unlike most scope mounts that seem to be horizontal.

Will shimming the scope help at all and if so do you shim front, back or both?

Is the problem to do with a bad mount design pull the scope to one side when the mount is tightened?

Am I just rubbish?

thanks in advance