Great scope for short money - Mueller Optics 4-16 x 50mm Adjusted Objective Tactical Rifle Scope

Not sure if there really is any free lunches in optics, bought one of these 3 years ago, was pleased with for the money, however I soon found out the way it was mounted in the rings it was doing some very strange tracking issues.The factory informed me it would need to be shimed up so the scope was in the middle of its tracking range
To start with or it would never track correctly.??? Ok, we did that and it worked ok for 6 mos, then wouldnt
Hold zero. Sent it back, they replaced it, second one lasted year and half, same problem....... replaced it with
A Weaver Kaspa 3x12x44 30mm side focus. Will review it shortly.