^^^ I had problems with my Vortex also, was a shame because I have only heard good things about their products. I purchased their 1-4x scope(from midwayusa) and was really impressed with it, mounted it in my larue spr-s mount. Loaded up 100 rds of my go to load of 178gr amax on top of 41.5 grs IMR 4895 w/ 210m primer and hit the range. After sighting it in, I got a few good sub moa 3 shot groups. Upon my final groups(80 rds later) I noticed my shots were all over the place I went to adjust windage and the turret completely de- threaded from the scope body. M-fer, So f-ing pissed. I went home got on the computer and looked what to do with Midwayusa, printed out the return slip and tried to calmly fill it out. All in all midway was good to me and fully reimbursed even w/ shipping costs. Pissed me off because I wasted all those components for nothing. I use to not sweat ammunition but times suck right now.
This was back in April 2013. Eventually I am going to purchase another 1-4x for hunting and etc., really want one without exposed turrets. I have a swfa 12x for bench and prone work at the moment, it is a nice scope for the money.
http://www.midwayusa.com/product/462883/vortex-viper-pst-rifle-scope-30mm-tube-1-4x-24mm-2-10-mil-adjustments-illuminated-tmcq-reticle-matte