I have a Ruger Hawkeye in 223 and have had several 1 inch tube scopes on it. Now I have found a Vortex Viper PST 6-24 to put on it, but don't have the necessary 30mm rings. I'd order some, but don't know what height I need to make sure the 53mm exit bell clears the barrel. To save me from doing endless research, do any of you already have the answer to my question? I'd sure appreciate it.