For the price these rings can't be beat. I had no problem mounting to my gun, nor mounting the scope. I bought them for the 30 mm application on a .22 mag, bolt action rifle (3/8 in scope mount). I had a very hard time finding rings to fit the bill, and when I came across these on Amazon, I thought I couldn't lose for the price. I was pleasantly surprised. Of course, the machine-quality is not the greatest, but once again, you get what you pay for when it comes to that. With these, I was satisfied with their application.