SP-5 Edd Evans is smiling about something but it is unlikely that it is his rifle, an interim model M-16 with open prong flash suppressor and un-chromed firing chamber. Although an improvement over earlier models with the addition of a receiver equipped with a cartridge seating plunger and a cleaning rod in the stock, it was prone to misfire if carbon accumulated in the receiver. Seating the round with the plunger resolved the problem but in the confusion and fear during hostile contact, an annoyance like this could lead to tragedy. That open prong flash suppress was good for twist opening the banding on cartons of C-rats, but tended to get snagged on vines and brush in the bush. I inadvertently discharged an entire magazine when my finger unintentionally tightened on the trigger while set to full automatic during a thoughtless attempt to pull it free of a clump of vines that had tightly wedged into the open prongs of the suppressor.  The Division received the improved M-16A1 rifles mid-year 1968, and the older models were issued to non-combatants and medics (the North Vietnamese did not subscribe to the tenants of the Geneva Convention and although the US did, medical personnel were permitted to carry weapons for their own protection). Beginning early in 1969 there were enough of the improved models available to issue to all troops. The early and interim models of the M-16 were oldies but definitely not goodies.