safe range on blanks is 30 feet, although we're told if we're on area's where there might be civilians (dog walkers and the like) and we see them, we have to aim off at 100 feet. Ultimately it means shit, atleast in the British Army due to the Blank Firing Adaptors (
big yellow things on the end of the gun) on the rifles which allow them to fire as fully and semi automatic. These block the ends of the rifles so that the gases produced by the firing of the cartridge can recycle and reload the next round. Veg can prolly tell you more considering his life is working on these rifles. And it isn't really that bad, if you get shot point blank in the face, its going to be damned dangerous but otherwise you'll just end up with a nasty rash, a load of molten metals come out the end causing it. I've come back off of excercises with huge rash's along my face where the dick next to me on the firing line has been shooting right across me. If you have some common sense, there is no way you can be killed by blanks.
Infact I'ma be putting this into practice this weekend doing Fibua in wales, ranges for shooting will be smaaaalll.