TV Guide National Geographic Channel Friday

Sean Rich, Larry 'Hammer' Harley and Jim Green travel to Colorado for an extravaganza of military collectibles, where Sean examines a 76lb bar of silver that may have come from the most famous Spanish shipwreck rescue in history. Hammer inspects what appears to be an authentic Keris sword with magical properties, while Jim goes to the shooting range with a Civil War re-enactor to see if his 1853 Enfield rifle fires

Bidders vie for an 18th-century flintlock, a four-barrel gun so complex and expensive to produce that only the wealthy could afford one, making such items highly desirable. Sean Rich and his fellow Lords also inspect a piece of Second World War memorabilia possibly used by couriers behind enemy lines, which if authentic could be valued at $18,000

An investigation into the eruption of Mount St Helens in 1980, asking why scientists failed to predict the disaster. The volcano exploded in a cloud of red-hot ash, killing 57 people and laying waste to 230 square miles of woodland after more than 120 years of inactivity. The programme assesses the possibility of such an event happening again