To save money Robert McNamara ordered that the ammunition for the new M-16s being sent to SEA in the early 60s use an older (dirtier) type of gunpowder meant for use with the M-14.

"Results": [
    {
        "TypeName": "PER",
        "Text": "Robert McNamara",
        "Start": 14,
        "End": 29
    }
]