I bought a 12mm riser just before the match this spring but it put me shooting 8" high at 200 yards with the sight on the bottom.
This one puts me at 35 clicks down from the top at 200 yards and I can shoot at 50, 100, and 200 yards with the same setup.
This was shot with CCI Mini Mags from a bench using the front half of one of Gunny Turners 1907 slings for support.
The shoot-n-see targets really helps to see those .22 sized holes at 200 yards. They are normally a bit tough to see even with a good scope.