A guy in Boise showed me a trick with a broken firing pin spring
This was maybe two years back, a fella brought in a really old .22 bolt action that wouldn't fire. The firing pin spring was totally shot, and he didn't want to wait for a mail order part. He was an older machinist, and he just took a ballpoint pen spring from his pocket. He cut it to length with some side cutters, then used a butane torch to heat and anneal the last coil on each end so it wouldn't snap. We popped it in, and it ran like a top for a test cycle. He said, 'Sometimes the fix is in your shirt pocket, not the parts bin.' I've used that trick three times since on plinking guns when a customer needed it fast and cheap. Anyone else have a good field fix for a small spring in a pinch?