I look at it this way...it's not even how big of a gun you're carrying and trying to conceal, it is more of a matter of how you carry yourself as to whether you're likely to "get made".
My best friend who is not a cop, but an avid shooter and competitor, is always amazed at how fast I can pick out someone who is carrying. The obvious giveaways are the shoot me first vests and the tacticool clothing with TACTICAL and 5.11 all over them. You see some goober decked out in his five-leb'ms, sleeved out, and trying to look operatory....you know he's packing. You see the guy wearing the shoot me first in 110f heat...yeah...he's toting a roscoe. No biggy. Duly noted. Those are the obvious tells.
The "I don't know how to carry my gun" tells are next. Usually it's a guy carrying in a cheap nylon gun show special holster that would print under a raincoat. The holster doesn't hold close to the body and it's flopping all around on the 1" dress belt that isn't suitable to keep pants up, let alone hold the weight of a pistol. Those are too easy. The good news is that his gun isn't a danger to anyone but himself because he's never going to be able to get it out of the holster on the same day he needed it, let alone in the same moment he might need it.
Then you have body language tells. The relatively new gun carrier, or guy who isn't really competent is always checking the location of his gun to "make sure it's there". Whether they realize it or not, they are ALWAYS putting their hand on the grip or patting the holster for reassurance. Then, if they aren't doing that, they walk favoring the side their gun is on. They always seem to be trying to put the gun side away from people. There is nothing necessarily wrong with this, but to someone who knows the cues, it is a neon sign. Then you have the "clamping the arm tightly to the side over the gun" guy. He has his arm rigidly covering the location of the gun and not moving it...ever. I like guys like these. They are easy peasy to spot instantaneously.
The guys who are harder to spot are the ones who dress smartly to their gun. Personally, I eschew ANYTHING that has TACTICAL on it. I own two "concealment vests" from 5.11 but the only time I ever wear them is when I am shooting an IDPA match, or a BUG match where all my work is from concealment. I never wear them at any other time. Mostly because I don't like them as an article of clothing but they scream GUN GUN GUN. If I am at our place in Prescott and I am wearing a vest because it's cold...it is a Woolrich or Carhart vest over a good plain flannel shirt. Nothing "tactical" about it.
Funny thing the Woolrich and Carhart vests conceal the hell out of the Smith 629 Mountain Gun or Glock 20 I usually carry up there, even though they put me at a severe disadvantage because they don't say TACTICAL on them...lol. (We have the occasional bear, mountain lion, and coyotes on our property, however I am not really concerned about a black bear or mountain lion...mostly I carry it for feral dogs and javelina). My "tactical" pants are Wrangler cargo pants with the "tech pocket" and comfortable hiking shoes or boots. I look a whole lot more like a middle aged gray haired hippy type in my "get back to nature" clothes than a retired cop with a gun he knows how to use a whole lot better than most folks.
The only "tell" I have is my SWAT shield tattoo and my 1* Blue Line tatt on my forearms that I got in a moment of youthful exuberance. But to be fair, only other officers really know what it is. I have been asked a couple of times if I used to be a Navy SEAL or Infantry by people who notice the eagle on the tatt and mistake it for a SEAL eagle tattoo or a First Infantry patch, to which I ALWAYS say "No".
My gun, my spare mags, my Spyderco folder, and my flashlight are all hidden. The only thing about me you would notice is that I am 6'4" and 290lbs, so I am not exactly subtle...but nothing about me screams GUN GUN GUN.
In the summer, especially in the valley when I am not in Prescott...I wear Wrangler cargo shorts, a cotton t-shirt with a cotton short sleeve shirt over top of that. It's the "summer uniform" for LOTS of folks in the valley. None of it is "tacticool" but eminently practical for keeping the sun and melanoma off as well as effectively concealing a pistol.
This way, I ignore all those pesky NO GUNS policy signs and not worry about "being made" just because I do my best not to stick out like a ***** at Disneyland and announce to the world I am carrying. Hide in plain sight.
Just my not so humble opinion.