6. The Firearms Used In The Film Are Real
As with most action films, the firearms used by the bad guys and our hero McClane are in fact real and modified to fire blanks. Modern, small arms ammunition is intended to have minimum muzzle flash, but director John McTiernan wanted vivid, "exaggerated realism" in the film and thus the muzzle flashes were said to be "deafening" in the film, to the point that it caused the aforementioned troubles for Alan Rickman. Normally most sound effects come from a studio library of sound effects. Sound designer Richard Shorr didn't want to use these clips however, because he thought modern sound equipment would show their age, as some of them were recorded in the 1950s and would sound a bit corny. To get around this and further the "exaggerated realism" wishes of McTiernan, the sound crew took the firearms to a firing range in Texas and recorded them being fired with live ammunition. This didn't work out too well for Bruce Willis, but more on
that later.