I’ve been enjoying John Connolly’s Charlie Parker series.
https://www.johnconnollybooks.com/the-parker-series
Starts off with gritty detective style material, but as the series progresses it starts to get involved with the supernatural as well as some non-mainstream religious issues (fallen angels, pagan gods, etc).
Don’t know if Connolly is a gun enthusiast or not, but find his choices of firarms interesting. Parker starts the series with a S&W 1076. There’s a hitman who goes around with an arsenal in his trunk (and he’s good comic relief as a homoxexual, black, super-conservative republican).
cc