A local gun dealer has a used rifle for sale that he describes as "Custom Brno VZ24, 29-1/2in Barrel, Donaldson Wasp." While I'm not really interested in the rifle, I'm curious about the cartridge. What's a Donaldson Wasp and why the jumongous barrel? I haven't physically seen the rifle yet, so I don't know what size the bore is. Could be a .17 or could be a 3/4" drainpipe.