Quote Originally Posted by Texas10 View Post
My Viper HS suffers from a locked up reticle if I torque the rings over 17 in lbs. The rest of the time, after making an elevation adjustment, it takes a few shots before it settles in. I've since purchased a Sightron III and now would never go back. That being said, I've got an older Vortex Crossfire II that has crystal clear optics and behaves perfectly. Go figure!
The old Horus Vision scopes would often have the side focus mechanism lock up if the ring was in just the wrong spot. As I recall the cause for stuff like this is tube walls that are too thin and clearance between the erector assembly and the inner wall of the tube that is too small. If a scope can't take at least 20 inch pounds of torque on the ring top screws without locking up, it is defective in my opinion. If you really need to use it as is, there are a couple of ways you can keep your scope from slipping with only 15 inch pounds on the rings - dusting the inside of the ring with powdered rosin or coating the bottom half of the inside of each ring with a silicone sealant such as GMS or electricians paint on wire sealer. Using wider rings will often work as well, with or without the rosin or sealant. I too gave up on the lower end Vortex models years ago and switched to Sightron. A no questions asked warranty is great, but not that great when your hunting trip or an important match is ruined by a scope failure.