Redding dies are some of the best mass-produced dies available. Their weak point is their lock rings, as Tom mentioned above. All modern threaded dies are threaded to a standard 7/8-14 TPI thread, and can be used on all modern reloading presses, except for a very few - the Dillon SDB (Square Deal B) press comes readily to mind.
If you don't want to replace the Redding lock rings, remove the setscrew and put a piece or two of lead shot in the hole, then insert the screw, adjust the die, and tighten the screw firmly. The lead shot will mold to the die threads, and give the screw a good grip on the die body.