My wife likes to use her 20 Ga. 870 youth when training for HRC. It was hard to find 20 Ga. blanks. I purchased a BPI 20 Ga. roll crimper from Mid-Way USA for $22.00 and a 100 count of primed 2 3/4 " hulls. It works great. I put the roll crimper in my drill press and set the desired depth. This rolls a hundred in a few minutes. These 20 Ga. blanks turn out identical to the 12 Ga. blanks you can buy on-line.