did some math on the m16a1:blockhead size
since the lego minifigure is what the blockhead was originally made of, it can be assumed that the blockhead is the same height as the lego minifigure; meaning, the blockhead is around 6 studs tall. the accepted size of one lego stud is 1 foot in the lego universe, meaning the minifigure is 6 feet tall.
now, the m16a1 is just about 1000mm (or ~3' 4" tall), so the ratio of m16a1 to blockhead is 3.4:6, but can be rounded to
3.5:6 or 5.8:10 for ease of modelling.
graphic:
