We have started the 1000 Joule homemade airgun challenge more than a year ago and increased the energy of our home made plumbing parts based arrow launcher very much since then, reaching 917 Joule as a maximum. But we had to stop the work when the fall came last year due to cold weather (bad for the performance of both rubber and compressed air). This year, we started with a new, optimized weapon and exceeded 550 fps with a regular crossbow bolt...

But in order to maximize the energy, we have replaced the smallish bolt against a solid stainless steel tube with an all steel tip, made from a professional grade center punch...

See how the tests went! Amazing results, really - both numerically and physically.

A "The Slingshot Channel" Production.