I've mounted a Vortex Viper HSLR on a Ruger 6.5 creedmoor and sighted it to 200 yds. The dial had to be twisted so much that I'm now limited to 22 MOA or just under one twist of the dial. This limits the range of the rifle to about 600 yds. Anybody have recommendation on how can I go about getting more MOA adjustment out of the scope? Obviously, 600 yds is more than plenty, if not excessive, for hunting but it would be fun to practice shooting targets longer range.