This might sound like a stupid question but I’ve been wondering every since S&W came out with the new slim 9mm.

I edc a glock 26 with a mag adapter so that it will fit glock 19 mags. So instead of 20 rounds total (the mag in my gun and a spare) I get 30.

Is that over kill? I keep seeing this trend to fewer and fewer round counts and I’m wondering if this is tactically sound or if its just a marketing gimick to separate gun owners from their money.

Opinions are welcome cause I’m definitely confused. Oh and as a side note I do have training and practice and consider myself to be proficient with a handgun.