The Internet Archive has incredible repository of public domain moving images. There are some amazing government news and information (and propaganda) films from WW II and later.
US Army Training Film on the XM16E1 rifle, the first mass-fielded version of the M16 rifle. This is the version with chrome-plated bolt carrier, no trap door in the buttstock, no forward assist, non-chrome-lined chamber, and three-prong flash supressor. Somewhat notorious for reliability issues in the jungles of Vietnam, it was upgraded into the much more reliable M16A1 in 1967. Most of the basic information in this video is just as true today for the M16A2/A4 and M4 carbine.
Audio/Visual: sound, color
(also of interest, these short films)
This Kodachrome film shows how a teenage boy learns to become a safe and accurate shooter. Famous riflemen appearing include Ned Lilly, Dick Shaughnessy, Thurman Randle, and Fred Armstrong.
(1) The Arsenal For D-Day "Equipment for Invasion In a U.S.A. port we see the materials of war being feverishly loaded into vessels. Planes are lifted to the decks of bulging ships, ships that are loaded to the water line with freight for the invasion. Slowly, then, the ships converge, to set sail in convoy. In Bratain we come upon acres and acres of piled up materiel and equipment, for the invasion armies on the Second Front...
(1) "Mediterranean: Amazing pictures of the great air-sea battle between an Allied Convoy to Malta, and Axis forces. Allied guns fill the air with bursting steel that brings many Nazi and Italian aircraft to sudden destruction. Allied marksmen thwart suicide attack of Italian torpedo plane." - naval combat footage of attacks on the Alexandria convoy (2) Local: Scots Cheer Royalty. (partial newsreel)
Salesmanship and psychology instruction for gun dealers.
Great stuff, btt.