On the subject of potato canons, this is the remains of one I built a few years ago.
I went a little overboard. It’s nearly 7ft long.
First time I used it, the BBQ lighter trigger exploded in my hand and it blew the screw cap clean off the end.
Some bad cuts and bruises to my hand and tinnitus for days. Very lucky not to have lost fingers.
Never found the potato. View attachment 526682View attachment 526683
Have you considered rebuilding it with less power, a shorter barrel, and aiming the spud at a metal grille target. FIre it using a lead. Wear ear defenders, safety eyewear, and ideally anti flash.
Collect the chips and fry them.