Which semi-auto in .40 S&W (or your personal preference)is the smallest (for on body conceal), would you choose?
Not necessarily wanting to pay "Kimber" money.

I have a Springfield XD sub-compact .40 cal, great little gun.

Glock 26, or a Glock 39, 39 only available in .45.

s&w airweight .38

I have the Springfield sub-compact 9mm, and it is a great lil concealed carry gun, it comes in 40 as well.

Glock 26/27(9mm or 40), Walther PPS (NOT the PPK), or Smith J frame. The .40 has quite a bark/snap in the sub-compacts.

While not being a .40 the Kahr,the new ruger ,and a seecamp are very small guns but are .380 .

Glock 27 is my choice. A quality holster and belt will make concealing any handgun much easier and more comfortable.

+1 The tiny .38 snubnose is awesome. You can hide it anywhere and not have a problem.

Darn near any semiauto that can be chambered in .40s&w can also be chambered in .45acp. That's my personal choice in caliber. You might prefer the .40 s&w so it's entirely up to you. Ammo is usually more widely available/found in .45 as oppesed to .40 so that may or may not figure in your selection Now as to the smallest semiauto,you can choose between traditional 1911 single action style or the newer striker fired semiautos. There's a bewildering selection out there and NO certain 1 is going to be better than another in reccomending something for YOU. You'll have to handle several different 1s and see which fits YOUR hand and points for you naturally. Naturally everyone has their own personal preference based on what works for them-that don't mean it'll work good for you. First,decide the action type/style is best suited for you. After you decide this,you can handle the guns within that catagory to see which fits you best and which offer the features you want. The best place to go to check out examples of different styles is a large gun store where you'll be able to handle as many as possible. If it fits you properly,you'll be able to simply bring gun up,and already automatically be pointing exactly where you're looking. Single action 1911 style SHOULD be carried cocked & locked-even when cocked,they still have multiple safetys preventing accidential discharge. Double action only or striker fired usually require more effort as the trigger (especially in dao) will be heavier.