I use their 220 grain 30 cal bullet in 300 Blackout. I have no idea how they hold up to 223 velocity, but my Blackouts are subsonic! When loading the bullet be sure to put a real flare on the case mouth to keep from damaging the plating, but keep the flare as small. Make sure your neck tension is .003 or .004 tight. That will hold the bullet in the case under recoil or keep the bullet from pushing back while chambering. With good neck tension, you only need to crimp enough to close case mouth not crimp it in. (This also protects the plating!)
Measuring Neck Tension: Before sizing measure neck all thickness, usually .015-.017, times both neck walls= .030-.034 + the bullet diameter .224 = .254-.258" subtract desired neck tension of .004 Puts you around .250-.254" after sizing (If smaller is OK if larger You need to size neck smaller) Them you can seat the bullet, it will expand the neck and you can measure if you want and that will tell you the exact neck tension. (If you don't own good measuring equipment- measure after sizing and after seating that give you a very rough idea. Try pushing seated bullet in to the case, if it won't go you are great! If it went half way easy you have a problem.)
Ivan