For me, it would depend on which SHTF situation. And then I also don't want to go pie in the sky since I actually think S could HTF soon.
1) natural disaster, most people not hurt, but help ain't coming soon. Rule of Law will return sooner or later.
9mm handgun like Glock 19 with at least 4 mags in my pockets, concealed.
Shotgun on a sling behind me.
"How can I help you? Oh don't mind this big gun...it's just in case."
2) Marxists take over after total monetary collapse (they caused), marauding gangs of browncoats coming into my town.
.45 ACP handgun like XDm45 with 4 mags on a thigh holster.
.223 AR-15 with as many mags as I can carry on a vest.
"Where's the militia mustering?"
3) Total collapse after major population die-off.
Shotgun with 00-buck, slugs, and birdshot
.22lr semi-auto like Ruger 10-22
"Where's that pesky wabbit?"
.45acp, .40 S&W, 9mm, .38 Spl, .380 acp, 22lr
12 gauge, .223/5.56x45mm, 30-30 Winchester
2 Chron. 7:14 Christians must seek His face