Aired: Apr 15, 2015In the next episode, Gary Archer, a World War II weapons expert, joins forces...

The Gunny heads back to Camp Pendleton to put the Mark 19 automatic grenade launcher to the test, and then swaps equipment for a nostalgic experience, firing the 1841 12-pound Mountain Howitzer and 50mm Krupp Mountain Gun alongside Gary Harper, a history enthusiast.