I put a new slide (Caspian) on my old #17 - now it fires when I pull the trigger AND when I release the trigger??  Trigger bow, trigger & block, all stock. I used parts from old slide on new one. Is there some sort of miss match or dimensional stack-up?
Any help with the cause, and cure would be appreciated. Thanks!

Well, apparently there ARE some differences between the original Glock slide and the Caspian Glock slide! The original striker embossment (the little part the trigger bow catches on to fire the gun - don't know the proper name) has more to it (is closer the the bow) than a replacement light weight striker. The old striker was rubbing on the bow holding it back and causing it to fire when the trigger was released! I put the new striker on the new slide ––- runs fine!!  FYI

Wow never heard of that.

A friend of mine had that problem and I replaced the CONNECTOR, which solved the problem.

Don't be so ham fisted putting it together.