Would expect flawless at this price point - Vortex Viper PST 6-24x50 FFP Rifle Scope

1st Vortex Purchase based on Warranty. The Glass is clear on Sunny days but only up to about 14-16 power. I'm sad to say after over $1000 investment total, a year of fighting with this scope to hold Zero I sent it back on warranty. Checked everything 3x including replacing custom machined/match scope rings for Vortex $100 Match Scope rings I aligned and hand lapped at their technician/engineer's suggestion. Torqued EVERYTHING to spec (16 in/lbs max on rings). Multiple calls to tech support at Vortex (They are nice). Multiple calls to valued firearms experts in my network and with over 50 successful scope mountings to my "Credit" sometimes it's your own stuff that you just wont give up on! After sitting in my safe for months it was 2 - 2.5 Mils off in windage and elevation. No explanation, I had to rezero it each outing, could not zero at 200yds, adjust turret to 100yds, then go back 200yds and it would be again about 2 - 2.5 Mils off? Finally after re-zeroing this last time I tried the box test (20clicks down, 20 clicks right, 20 clicks up, 20 clicks left and it was off after just 15 rounds (.308). Went back to my Bushnell Banner until I get the Vortex back. (credentials - 30 year firearms instructor multiple disciplines, 640 Contact hours Formal Education in Firearms Manufacturing, Certified Machinist, Gunsmith)