On a lighter note ! http://www.thefirearmblog.com/blog/category/air-guns/ Check out: - The Gas Sub Machine Gun : The gun shoots BBs at 600 fps. If it was able to achieve this with even the heaviest .22 BBs it would only generate just over 12 ft/lbs of energy. Before you get too excited about defending your castle with this legal-to-own-without-paperwork machine gun, it is defiantly not a toy but is not nearly powerful enough for self defense. The GSMG is currently a prototype and the final product will sell for around US$350. - Nitron N-32 Gas Powered Canon : The Nitron N-32 is a semi-automatic cannon microprocessor controlled high pressure inert gas cannon. Is fires 1.250â€ steel ball bearings at over 1000 fps. That is about 3000 ft/lbs of muzzle energy. For comparison a 7.62x51mm NATO round has about 2600 ft/lbs of energy! The gun runs off either compressed Nitrogen, air or Helium. Its peak performance is at 1200 psi. Depending on supply pressure it can fire at up to 60 rounds per minute which, sadly, would be to slow for full automatic fire. - Incredibly Powerful Spud Guns : Most of Sureshots guns operate by injecting Methylacetylene-Propadiene gas into an expantion chamber and then igniting it. The BL-415, which uses the Methylacetylene-Propadiene gas system, can generate up to 450 ft/lbs of muzzle energy. That is around the same muzzle energy of a .45 ACP round! The 60" long tennis ball sized barrel of the BL-525 can generate 2000+ fl/lbs of energy if loaded with a proprietary 4090 grain UHMW/steel projectile. That is more energy than a 6.8mm Remington SPC cartridge! Impressive? You have seen nothing yet ... The below video shows a proof of concept developed for a Mexican defense contractor. It fires a 6790 grain projectile and generates 3000 ft/lbs of muzzle energy!!! That is more than a .308 Winchester!