That said (no, not what Timothy said; but the others

) I think there are some equipment factors involved, and they can be important considerations when choosing a primary handgun for concealed carry. If you pick up a stock G29 or G27 with a stock magazine (no extensions) and use standard factory ammo (no subsonics), my opinion is that even the very best shooters will have a hard time maintaining that sort of accuracy in rapid fire. They may come close in controlled-pair speed, but not in double-tap speed.
Very small pistols have become increasingly popular as the number of CCW holders grows nationally. Just a few decades ago, if you wanted a sub-compact sized pistol you were seldom looking at calibers even as large as .380. Today, you can get beefy calibers with good muzzle energy in very small pistols. The combination can make for a very attractive carry, but you'd better be prepared to practice a healthy amount with that combo and learn what you can and can't do with it. A lightweight, sub-compact pistol in 10mm or even .40 S&W doesn't give you much to hold onto, and doesn't put really any mass between you and the muzzle flip.
Then again, a 1.5-inch sized rapid-fire grouping at 10 yards isn't necessary for good combat accuracy. In general, though, a larger gun with a longer barrel will afford you a better potential for rapid-fire accuracy...basic accuracy, in fact. A longer sight radius means more precise aiming capability, and more mass and a longer mechanical action means less felt recoil.
I know this really doesn't have anything to do with your question, but I'm just notin' it for all the folks new to concealed carry who may be shopping for their first carry gun. Everything is a trade-off. Bigger guns are heavier and may be more difficult for some to conceal, but you can become more accurate with them in a shorter period of time (to a point: ain't talkin' totin' a S&W .500 Magnum here; but a Glock 17 is going to be easier to shoot well than a Glock 26). Small guns are easier to carry and conceal, but they're harder to use well. And if you put a snappy load like a 10mm in a very small pistol, you have some effective ballistics but a gun that may really bounce around on you between shots. I'm just sayin'.
Not back to your regularly scheduled programming...