The primary reason to carry a gun is "need".
I carry which ever handgun it is that fits my needs, for instance a couple weeks ago I needed to carry a large amount of money from my Bank to my home. Now entering a Bank with a huge "bulge" invites trouble from Security, Tellers, and Patrons with phones. So what do you do?
Simple carry the smallest gun that you can discreetly carry that provides an adequate response that will get you out of trouble.
I chose my Beretta 21A .22lr carried inside a Jean Jacket pocket and also carried a backpack (to use to hit my opponent or his gun away from me. My checks were inside the Backpack and I made a conscious effort to converse with the Teller and joke about caarrying my "purse" to divert attention away from my body and any attention to the small bulge in my front of the coat.
Tactica are as important as which weapon to carry.
Noone even paid attention to me, or my handgun.
I placed the Backpack on the counter and opened it wide to show the tellet it was empty except for papers.( DIdn't want to scare the Teller).
OK Tactics and Handgun worked.
Yes I would have preferred to have my S&W Chief along but it didn't fit the "Need"!