If you buy their higher priced rings they come with keeper screws to affix the ring to the scope before mounting.

I know, I know but "higher priced" is a phrase that gives me nightmares. I'm fiscally impaired, ya see.

If I had to buy another pair today however, I wouldn't hesitate to get the ones with the set screws. Well worth the ..... ugh..... extra dough! There, I said it.

Cheers!

Redial

Have Conetrol rings on my 35 Whelen and have never had a scope movement problem. Really like the smooth, no snag contour of the rings. Did get them 20+ years ago so don't know how the cost compares to other brands now.