Maybe change the M16's model maybe?
I already have a fix for it, i made the sights less chunky and i darkened the colors on the model.
and the mag is more round. and its a M416
Your barrels.
Waay too many poly's.
make it an octogon, and it would be good.
I made a new low-poly barrel for most of the guns, but i made it shorty after i made the others