In doing 223 blanks I sizing and key case as ordinary. I use between seven and 8 grains of Purple Dot. That provides it a superb loud noise and is particularly regular. I make use of a C H crimp die to finish it off. At times the shoulder will https://strapweaponshop.com/product/triple-r-munitions-223-5-56-nato-blanks-100-rounds/