Loaded a few 300 blackout rounds for a buddy of mine. Used 223 brass to form it into 300 blackout. It was pretty easy.
Case on the right is 223 and the left is the new 300 blackout.
I loaded up with 110grn Vmax and it actually had less recoil than the 223. I aslo loaded a few 208grn Amax for fun and it sounded barely louder than a .22 cal. I'm thinking about getting one now. :)