The IRA's Homemade .22 "Zip Gun" with firearms expert Jonathan Ferguson

From a channel Lumen includes in full: The Royal Armouries, the UK's national museum of arms and armour, has its curators (notably Jonathan Ferguson) examine weapons from the collection, separating documented history from myth.

A 20-minute video from Royal Armouries's catalogue; the title names its topic.

Video by Royal Armouries, played through YouTube's embedded player.