With urban fighting being the trend today, building to building, house to house and room to room, I would have to say the AK 47, 7.62x39, is the best choice. The M14, although a good weapon, was too long and clumsy for going through doorways and tight spots, the M16 did not have the stopping power at close range like the AK. Myself and other guys in my company preferred the AK in that type of close in fighting during my tour in Vietnam. The AK was everywhere and just about all the guys I was with carried one along side their Alice pack frame. The weapon was flawless and packed a better punch at close range. Most of my combat was in wooded areas in the north where we encountered small cities like Kontum, Dak To and others. There were buildings built by the French and we liberated many of them. I would have liked to have had a .45 Cal. Thompson Sub Machine Gun. My Seargent had one that he picked up from a Special Forces Captain. For clearing rooms, it was devastating to say the least!