My father fought with the 1st Marine Div, 1st Recon Bat, Charlie Company in 1970 - 1971. He went through basic with the M14, and said outside of it being a pig (heavy) and prone to rusting in the jungles he preferred it because of its ability to punch through jungle canopy and stop the enemy. He was issued a M16 in VN, but said they had M14s available and at least one of their Recon Team would always trade out. He said had it not been for the mission (mission drives gear) of Marine Recon he'd always chosen the M14. However, the amount of gear was exceedingly difficult to hump for multiday to week long missions.

When he visited once I opened my safe, and he reached right past six AR15s and picked up the one M1A in it. He never even asked or held the AR15s, but looked over the M1A very thoroughly.