Make sure you do not use Hornday One Shot spray lube that is prescription of stuck cases for sure. Dillon Spray lube or better yet Imperial Die Wax. Get some lube inside the case neck to help decrease the case stretching during the sizing operation. Get ready to trim, chamfer, and deburr!
The case of the 223 is not a big a problem with loading as the 308 is with mil surplus brass. If you now the heritage of the brass that is great, ie you fired it in your weapons. The heritage of most mil. once fired brass is from a sloppy chambered machine gun, ergo you probably would want to consider using a small base size die for the first sizing to avoid problems.
As with any reloading undertaking cross reference data and work up loads using a reduction of 10 percent of the max load. Your goal is accuracy, function, and reliability.
I would sort by case headstamp and the keep them as one lot. Keep track of firings and sizing operations for each lot.