I have a S&W 10-5 4" in excellent condition that I would
like to make a 2" out of. I found the barrel:

Smith & Wesson S&W Mdl 10 K-Frame 2" Blued Barrel : Barrels at GunBroker.com

What else do I need parts wise and has anybody had much luck doing this?

You also need the shorter ejector rod and associated parts. It is relatively easy to bend the frame while removing/replacing the barrel, and problems may arise with setting the barrel/cylinder gap without special tools, however. Have you considered trading for a 2" gun instead?

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Alan
SWCA LM 2023, SWHF 220