Flechettes ("nails" or "bee hive" round) were (and still are) loaded in a variety of artillery rounds. In Vietnam, the most common use were in 106mm recoilless rifles, 90mm guns, 105mm howitzers (used in direct fire), and 2.75 inch rockets fired from gunships. In storage since the Vietnam War ended.
LZ NAM was able to acquire a nice supply from government surplus stock. Pristine - No Rust and come in a package of eight (8). They are 1 inch in length...9mm round shown in picture is for size comparison only and not included with purchase. Stick 'em on your cap/hat as a reminder of "the good old days".