wow, you guys know nothing about firearms. Tony Montana was using a M16-M203. It had the jungle handgaurd with heatshield. The movie was in the 70's we just got out of Vietnam. The only full automatic assault rifle at the time in the US was the M16A1. The M4 was not around until about the late 80's early 90's. The basic differences in each A1, A2, etc. are the functions. A1 had the triangle handgaurd unless it had the 203. A2 was the round one with better internals. Then from there the internals change so that it is more functional. Hope this helps...
