I recently put together a .308 using a savage varmint action and a criterion barrel from nss. I upgraded the trigger to the rifle basics model 2 trigger and topped it with a vortex viper 6x20x50. On the range I have consistently been able to shoot .375 five shoot groups. I built this rifle for varmit and hog shooting at my deer lease. The issue I am having is after killing a dozen hogs and a few yotes, everything has started coming in 450+ yards out. I am looking to upgrade my scope to something that I can make adjustments and when I return the scope to zero it will truly be at zero (my vortex has consistently been 1.5" high after returning to the preset zero). I would like to stay in the $1000.00 range but would go to $1500.00 if there was a standout scope in that price range. Please let me know your recommendations and why.