If you can't find a store you may want to cruise this site and copy some images of ideas and either make one like most of us do here or have someone make one for you, either a metal shop for a "wire frame" slig shot such as a Trumark or Marksman or a carpentry shop to make a wooden one of hard plywood about 1.5cm or more thick. You will then need to find rubber either flat or tube and a little piece of good leather you can cut for the pouch. Ammo can be glass marbles, lead fishing shot, lead shotgun shot, ball bearings or pieces of rebar which reinforces concrete cut in 10mm long sections.
You will need to make a "catch box" as a target area which prevents your ammo from being lost. Use a large cardboard box with a rod or wood pole stuck through it onto which you hang cloth, either old clothes or whatever to stop the ammo. The ammo will fall mostly in the box if the rod is almost all the way in the back of the box. Put a sheet of plastic in front of the box for when ammo bounces out or place the catch box on concrete or other floor. A catch box ought to be about a half meter wide, half meter high and half meter deep and start shooting at about four meters until you mater hitting a 10 cm target, then move back meter by meter. The "standard" range is 10 meters but that isn't important, whatever range you like is what you use. It's fun to vary ranges.
Edited by Chuck Daehler, 02 April 2015 - 10:47 AM.