Metal jacket filled with????

Ceramic bullets have (or were) used for practice by some branch's of the military in indoor firing ranges,, (I visited such a range in San Antonio a few years ago)

Visited a another facility where the Military was using air-powered replica's of hand guns / rifles / SAWS,,, taking aim at a 'Virtual" infantry invasion projected on the wall. Firearms were true to size and weight. Air was used in the weapons to simulate recoil. (A multi-million dollar version of a multi-player Atari!!!) Computer registered hits/misses/ammo used in a certain length of time, etc etc etc, .

'We' (Construction Representatives) were allowed to try it out. When finished, the Instructor told us safest place for the enemy to stand was directly in front of me! (I should have been using a SAW instead of the 45 pistol!)

BUT,,, back to the topic, it will be interesting to see if they come up with something that ~works~ and can be enjoyed by all!!!! (I guess that depends on what end of the barrel you're on!!! LOL!!)