The cross-bolt style lock rings from Hornady and Forster lock in place very securely. Lyman also makes a cross bolt lock ring, but does not include it with their dies. RCBS used to have cross-bolt lock rings, but switched to set screws quite a few years ago. They look very similar to Forster cross-bolt rings, but have allen head clamp screws instead of phillips head as on the Forster. I find them every once in a while at gun shows for cheap.
Andy