I will soon be getting a CZ 452 Varmint in .17hmr and want a high power scope but do not want to spend over $100 for a decent scope. What do you know about the Simmons 6-18x40 ProHunter Rifle Scope? This particular scope costs $70. Does it keep its zero? Will the point of impact change when the power is changed on this scope? I am not worried about the affects of recoil since it will only be on the .17hmr. If you have any other scope suggestions that fit this criteria, please let me know. Thanks.