They are cheap but they work. Used a torque wrench everything at 15 inch pounds and locktight. One my .300 wm with a muzzle break during load development no zero shift at all. not taking away from high end setups just wanted to say I'm very happy. I have the tactical style with six screws in each ring, 40 MOA base.
Not sure what prompted this but if you short on cash and need quality ring go with weaver.
"Let glorious acts more glorious acts inspire,
And catch from breast to breast the noble fire!
On valour's side the odds of combat lie,
The brave live glorious, or lamented die;" - Iliad, Book V