Originally Posted by skires
Edited for the sake of sanity ...
Anywhere in the UK that you can get long ( 6 inches or more ) 11mm to 11mm rails?
Will a standard 11mm dovetail fitting be ok on a BSA 13mm dovetail?
If an Ft shooter is just zeroing at a set distance and then leaving the elevation turret ( say 35y ) and using holdover/under, do they need to worry about shimming or MOA adjustment?
Shimming or sloping the rail is about either getting the scope in it's adjustment range, or even better optical centred and in it's adjustment range.
Slope doesn't change your trajectory, it just offsets it. So more or less makes no difference.
Scope height does make a difference, higher will push the top of your trajectory out, and give you less clicks (although it's usually in the region of 1) at 55, but many more at 10. In fact you are more likely to run out of clicks at 10yds than at 55.