if your a reloader and want a 6x45 get it. got my barrel on last mon. got the dies last wed. and been playing with it last couple days. makes a great companion to my 300 blkout. No special mags or bolts to buy, dies are easy to get and making the brass is made by running 223 brass thru a 6x45 full length sizing die. that's it. So far, ar 15 cycling does not seem to be quite as picky about powder types and charges as my 300. I've still got plenty of work ( I mean fun) to do