Concealed carry size and common calibers are still very broad. I can CC a Ruger GP100 with a 6-inch barrel length under the right conditions, a shoulder holster, and a loose-fitting T-shirt. What is common for what I possess and am capable of concealing may not work for your frame. Common calibers, I consider 38 Special, 357 Mag, 22 LR, 9 MM, 45 ACP, and 10 mm common calibers, simply because I find no need for rounds like .327 or 5.7X28 as "common", simply because they cannot always be found local to me.
Information is KEY to success, otherwise, it just sounds like you are trolling to see what people have. My $0.02, but with inflation, it is probably more like $0.00002.