Had the ‘pleasure’ ??once of using the H&R version of one of these critters at the fertilizer plant where I worked. We used it to launch the oil boom across the mouth of the barge slip every month for practice and unfortunately once in a while for real. It used .45-70 blackpowder blanks and shot a 3/8 inch brass rod and kicked like 2 mules. I allowed my younger coworkers to shoot it. I did have a steady supply of once fired .45-70 brass though.