The muzzle blast of a BP blank will make an impressive hole in paper at 4 feet Cowboy Mounted Shooters use blanks to break balloons at ten feet or more. Granted, the blanks are made to do this, but the main projectile is burning bits of black powder.
Never point a blank at anyone, even far off. (Guns are always loaded. Never point a gun at anything you are not prepared to destroy.) If you want something for play gunfights, with live actors on the receiving end, get one of the plugged-barrel stage-prop non-guns that fire blanks that vent to the side. Otherwise aim-off and never get closer than 10 yards.
Hollywood and the US military have a significant list of folks maimed and killed by firearms loaded with blanks.