Go to S&W's web site and request a owner's manual.
A Smith and Wesson M&P 40 is a .40 caliber hand gun.
No
250 or so
Used, maybe $200 tops.
Recommend you ask a gunsmith for assistance.
Smith and Wesson. It's the manufacturer who developed the caliber, a frequent practice in the firearm industry.
300-525 USD
Best to ask a gunsmith. You can request a manual from S&W also.
When referring to the .40 caliber cartridge, SW always stands for Smith and Wesson, regardless of the brand of the gun, because the .40 S&W cartridge was designed by Smith and Wesson. The offical name of the cartridge is .40 S&W, just like the official name of the .45 is .45 ACP (Automatic Colt Pistol). People have a habit of leaving off things they don't think are important, so the .40 S&W is commonly called just "40."
Best to have a gunsmith show you or contact S&W and ask for an owners manual.
Contact S&W for a manual or download one from their site or ask a gunsmith for help
.40 Smith & Wesson is a 10x22mm cartridge, whereas the .45 ACP would measure 11.65x23 in metric measurements. The .45 is a larger round, and also a much slower round.