Could be the striker assembly, or perhaps the aftermarket trigger kit causing the issues.
Did you install the kit, and did the kit include a different trigger bar? Just wondering if the firing pin safety is not getting pushed out of the way completely. If this is the case, you may see some abnormal peening on the firing pin block or the striker.

I don't think the guide rod would be a problem, unless the slide is not going fully into battery for some reason.


Carter

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Ret. LE, FA Instr, S&W Armorer