model 24 main spring assembly

[searay2100]

Hell everyone,I am new to the site but not on working on my own guns.I had a very good teacher in my father but am having a problem figuring out a simple way to reinstall the main spring assembly in my model 24 22 mag/20 gauge.I am replacing it as well as the firing pins do to the fact that it will not fire.I had a gunsmith look at it and all he did was give it a good cleaning when it really wasn't dirty.I don't think he was the sharpest tool in the shed.when I got it back they said they test fired it and it worked fine.I shot a dozen rounds thru it,both barrels and it worked fine until I tried to shoot it again and it was right back to click every time I tried to fire it.my best friend has fun calling it my pita gun since you couldn't kill anything with it short of using as a club to beat them to death.I would greatly appreciate any suggestions.thanks.

[Mad Dog]

Which series is it?

Does it have a side selector or is it on the hammer?

Serial number range?