Originally Posted by
jh9
You really should just take it to a gunsmith that knows how to do normal revolver maintenance. Troubleshooting over the internet is time consuming and error prone. Because once you've got the strain screw sorted out, then you have to check the mainspring (OEM, not Wolff) and make sure the hammer-mounted firing pin isn't damaged. The -4 you've got is maybe probably an early 80s gun, so you need to determine if it uses the newer spring-loaded hammer-mounted firing pin or the non-spring-loaded kind. Offhand I don't remember when they made the change, but that impacts finding a replacement. (Also the rivets are also out of production.) Then you have to check headspace and endshake, the latter being a problem that doesn't always show up consistently if you're just going by "does the gun work or not". Etc.
As a bonus, your gunsmith might have a proper, factory screw to replace the buggered one.