I have a older k22 ithas a hammer I think is a target hammer. a 1/2" top that grooved the ser # is in the 149000it Igot it in 1955 Is this hammer origional.And if so are they available?

I suggest you post a photo for us to look at.

On the serial number, I assume you mean K149xxx? That would be a 1952 gun. Perhaps you bought it used in 1955?

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Jack
SWCA #2475, SWHF #318

K136,691 – K175,637...1952 (manufacture). I don't quite understand your question about the hammer.