Unique has supposedly been cleaned up a bit some time around 2001. I have made some reduced jacketed bullet loads in my 30-30 with Unique. No experience with .223.
One of the best resources I have for questions like this is the compiled caliber specific reloading manuals offered by Loadbook USA. They compile all of the data they can get and publish it in a $5.00 book. I don't own the one for the .223, but if you got one it would tell you if there is a Unique load. Also, it would tell you the speer, hornady, lyman, IMR, Sierra, Winchester, and a few other sets of data for that cartridge. If you ever want to look up loads for any components you might have on hand like oddball bullets, or even extra powder you want to burn up, the Loadbook can be a big help.