Colt Manufacturing used NIJ funding to develop a prototype of a Smart Gun that could be fired only by its owner. It is currently focusing on miniaturizing the transponder chips and circuits required for the weapon to work. Law enforcement officials who saw a demonstration had mixes reactions to the new weapon. An even more sophisticated weapon being developed is called the rail gun. This gun uses an electrical current and a self-generated magnetic field to propel a projectile at tremendous velocity in a very short distance. It has potential for shipboard defense. Two nonlethal weapons under development are the Ring Airfoil Projectile and the High Energy Toroidal Vortex Launcher. Perhaps the most significant commercial development in the area of firearms and ammunition was the appearance of three new Block models chambered for the .357 SIG cartridge. Ptarmigan Corporation has introduced a series of after-market drop-in barrels for Glocks. Federal Cartridge has introduced a new line of Personal Defense Ammunition based on its successful Hydra-Shock line. Hornady has introduced it's a-Max ammunition in both .223 Remington and .308 Winchester. Laser sights are also becoming useful auxiliary sights and training aids. Developments such as combining designs, creating special-purpose ammunition, and fine-tuning existing configurations will continue to enhance the effectiveness of today's weapons. List of sources of weapons technology