Found this, bought some and they are great, Newlon competition die lock rings. 10 dollars each. Seems like a great deal for precision rings.
Competition Die Lock Rings
7/8 x14 Benchrest Competition Die Lock Rings CNC Built 17-4 Stainless Steel Our Lock Rings built to extreme tolerances for flatness and squareness for the serious competition shooter/reloader.
newlonprecision.com