The flash app 'Pimp My Gun' is now updated in it's newest version. Much more advanced than before with aaaaalot more options (for the guns available; M4, M16, HK416/417, SCAR-H/L, AK-47/74/74su, Dragunov SVD). Well worth checking out.
http://pimpmygun.doctornoob.com/ (Oops, forgot link)...