Buy a used golf club @ Goodwill for a couple of bucks.
Cut that tapered tube on the shaft into several 4-5" pieces with tubing cutters.
Use a chamfering tool chucked into a drill to sharpen the ends of the tubes. You now have a punch set of varying diameters. Chucked in a drill, they easily cut leather etc.
I like to use plastic playing cards to shim hard-to-replace breech seals, and even wobbly barrel-pivots.
Anyhow, just figured I'd share the tip.