Lots of people asked me if it was possible to give slingshot ammo (steel balls) some spin. That is of course not easy. The most obvious way would be to use a rifled gun barrel and push the ammo through it with a dowel. But. But but but. The dowel takes away a lot of energy. The dowel would have to be stopped, and it would have a lot of momentum. You can't squeeze a steel ball through rifling. The steel ball would be rather slow in comparison with a firearm bullet, so the rotation would be slow as well. How to solve it? Forget the dowel and the barrel, I just use a regular slingshot crossbow, much like my winch operated hand cannon. My idea is to rotate the whole slingshot gun. Based on Thorsten Dr. b. c.'s input during the "Galileo" filming here in Burgkunstadt, I just ordered a thick plastic tube (diameter 25cm), 1 meter long, and six rubber wheels for furniture pieces. All together under 20 Euros. The plan is to set the wheels up in two "rings", one at the front and one at the back of the plastic tube, and rotate the whole thing by means of a power drill, using some Thera Band as a transmission belt. The trigger will be a centered rod that is pulled by a wheeled hook from the outside of the weapon. The whole slingshot crossbow is inside of the tube, spinning madly (at 3,000 RPM). If the end speed of the bullet (20mm steel ball) is 50 m/s, this means it would spin once per meter. If I type in my parameters into this calculator http://www.bergerbullets.com/litz/TwistRuleAlt.php then the output says that the SG (stability factor due to the "Miller Twist Rule") is 2,47, which is truly excellent. Values over 1,5 mean "comfortable stability". I don't really know how to compare the results - as we all know, round balls need no spinning. But it will be an interesting contraption.