hammer question

looking at a hammer from the side, i can see a little peice of wire?? that looks like it goes through a channel up into the hammer, a small hole is completly through the hammer, with the “wire” flattened inside the hole… i’ve scratched my head, and scratched my ass, what in the dickens is this for???

keeps the hammer pin from walking out

J spring… Keeps the hammer pin from walking out.

o.k. guys,thanks. i looked that stupid thing over for awhie, trying to decide why it was there. i KNEW it served some purpose, or they wouldn’t have gone to the trouble to install it, which don’t look like fun. thanks again