In performing 223 blanks I size and prime case as regular. I use between seven and eight grains of Crimson Dot. That gives it a superb loud sound which is dependable. I make use of a C H crimp die to finish it off. Often the shoulder will buckle a https://strapweaponshop.com/product/triple-r-munitions-223-5-56-nato-blanks-100-rounds/