IMHO Warne are about the best available for under a hundred bucks a set. They use a Weaver style steel base and vertically split steel, powder coated rings. Unlike Leupold, and most other horrizontally split rings, the vertically split Warne rings almost never twist a scope when you tighten them down.

Weaver style bases and rings are known for their incredible strength and durability. Look at all of the tactical bases and rings that LE and the military uses, including those that sit atop the big 50BMG's. They are all Weaver style bases and rings.