Adrian Armsby

Hi all from a new member, can any of you experts out there help me out with a problem I'm having with my nitesite viper, my scope is a hawk 6x24x50 fitted to a .17hmr cz 455 zeroed at 100yards. The problem is when the viper is attached it's approx 2inch high at 100yards, has anyone got any ideas on what I'm doing wrong , every thing is tight fitting and secure, thanks guys, from Aidy