M79 Footage - Need Help Locating Source

Hi guys! I've found some great footage of the M79 Grenade Launcher, and I would love to know where it is originally from. Looks to be some kind of old training films, but I can't pin down the sources. Anyone have any ideas?

M79 40mm Grenade Launcher - YouTube

M79 Grenade Launcher - YouTube

That would be the standard training film for recruits. Military made and owned.

I believe it came from an Army TV production call "The Big Picture". Shown weekly during the 1960s.