Bill, I suspect it's the cartridge indicator spring instead of the pin itself. It is either broken or perhaps gone completely. Gun Parts Corporation
www.gunpartscorp.com would have a replacement for little of nothing. If you can disassemble/assemble the slide with confidence, replacement shouldn't pose a problem. If you don't feel comfortable doing that yourself by all means take it to your local smith. If you don't have anyone near you, e-mail me and I'll send you disassembly instructions and help you all I can. George