Thursday, June 7, 2012

"Throwing knives" as ammo - now 86% more deadly

Most of you might have seen my latest "crazy ammo" contraption, a slingshot crossbow that shoots throwing knives. I demonstrated it with a fairly easy 18 kg (40 lb) band set, and it was already impressive.

Have used my own band dimension calculator now, entered a 25mm steel ball that weighs the same as one of these knives...


This is 1,86 times more rubber than I used for the video... about 75 lbs of a draw. This brings the simple wooden construction to a limit. But the energy of the knives now exceeds 100 ft-lb for sure. Downright scary. Ricochets are super dangerous. Don't do this at home.


  1. Haha, good news. I'm looking forward to see it operating in a video next weekend. Also on 'crazy targets' like coconuts and watermelons (or your car-tires ;)

  2. Hallo Jörg,
    teste die Messer doch mal mit einem Schweif :-)

  3. Jorg my friend you are a mix of Conan the destructor and Atilla.


  4. "Super Dangerous" and "Don't do this at home" got my immediate excited attention. Needless to say, I am looking forward to seeing this in action soon. All the best!

  5. Hello!
    I am a Taiwanese.
    Your works are very cool.
    I want to made a slighshot rifle by myself.
    I don't know how length and wide about the band.
    This is my sketch.
    I will use theraband gold and 3.6gm steel ball
    Could you suggest me how length and wide about the band?
    Thank you very much.

    My English is very poor.
    Please forgive me.

    1. Here is what the band calculator says.


      Your ammo weighs 3.61 gramms.

      Cut the bands 20.49 cm long.

      Band width at the fork is 3.88 cm.

      Band width at the pouch is 2 cm.

      You need 1 bands per side.

  6. Awsome! Would it be possible to make a repeating version of this with a magazine box?

    Also on a older topic, from the EntropySlayer 2k idea, would the bands retain more power if relased a.s.a.p. after draw? Before the cooling process is completed?

  7. Wha ! deadly stuff. Just glad you're not mad at me.