I've shot and recorded 7 different 165gr Flat Point rounds indoors through my S&W M&P 40 and they've varied from 899 up to 1153 fps in 10 shot groups measured 5 ft from the 4.25 inch barrel. 4 brands of FMJ (Full Metal Jacket) clocked at an average of 899, 971, 1026 and 1077 fps, while 3 types from 2 brands of JHP (Jacketed Hollow Point) defensive rounds ran a little hotter at 1082, 1097, and 1153 average fps. All of these were brand name factory ammunition with the exception of the fastest round @ 1153 FPS, it was "new brass" ammo from a commercial reloader labeled as .40 S&W +P @ 36,000 PSI, 1170 FPS, 502 FPE, 4 in. barrel.
Another major commercial reloader told me in an email that their new brass .40 S&W assembled with 155gr S***r Gold Dot (JHP) bullets "155 +p has 1200 FPS and 496 FPE while the 155 +p+ has 1300 FPS and 582 FPE" (Foot Pounds Energy) with pressures of 36,000 and 38,000 PSI respectively, but their customer service rep. (probably the owner/president) also cautioned me by writing "I have fired both these rounds in a M&P with no problems. I do feel that the +p+ round would shorten the life of the gun if it was fired in excess."
The SAAMI specification for .40 S&W is 35,000 PSI (same as .357 Magnum) and they don't list a .40 S&W +P spec. although SAAMI spec for 9mm Luger is 35,000 PSI and 9mm +P is 38,500. BTW, the SAAMI specs for the .45 ACP are considerably lower at 21,000 PSI normally and 23,000 PSI for the +P loads.
.40 S&W +P ammunition is not recommended unless the chamber fully supports the case head. Note that the .40 S&W G***k (G22, G23, G27, and G35) does NOT fully support the case head and most ammunition manufacturers recommend avoiding overpressure ammunition in non-fully supported firearms. The .40 S&W G***ks are excellent pistols (especially the G35) and are known to handle most/all SAAMI spec. brass/copper jacketed factory ammunition exceptionally well.
Finally, my favorite 165gr SMJ (Soft-point Metal Jacketed) bullet's outdoor performance is nearly identical to the 165 gr FMJ listed above (1077 fps @ 425 fpe.) The *brand name omitted* SMJ/FMJ groups the best for me. Shooting offhand open sights at 25 yards from a clean/cold barrel I usually place 6-7 SMJ or 8 FMJ out of 10 tight enough to be completely hidden under a business card centered on the target (vertical business card is my standard for the cranio-ocular cavity). Because of the SMJ's barrier penetrating ability and consistent expansion I load them as the bottom 10 rounds in my carry magazine, right under 5 - 180gr W********r R****r Bonded LE JHP, 1072 fps @ 459 fpe which also group very well from my pistol. From the relatively few times I've fired the 180 R****rs I can tell you that their kick is a little snappier but easily controllable.
I hope this helps answer your question.
Introduced Jan 1990.
.40 CAL HAS MORE VELOCITY AND ENERGY AT IMPACT
Very generally speaking, it is a 9mm diameter bullet fired with the pressure of a .40 SW, so what you get is a very high velocity 9mm bullet which has much more muzzle energy than a regular 9mm. They are very loud because of the higher pressure (more powder) but very accurate, and based on the (somewhat limited) information available about it, is very effective.
You need a gunsmith.
the maker.
+P has more muzzle velocity
100-400 USD
100-500 USD or so
Assuming you mean caliber, the caliber simply refers to the diameter of the bullet the gun is designed to fire. American cartridge sizes are expressed as tenths or hundredths of an inch, and European cartridges sizes are expressed as millimeter. A .40 caliber gun fires a bullet that is .40 of an inch in diameter. A 9 millimeter gun fires a bullet that is 9 millimeters in diamter. There are too many variations to list here, but some common handgun calibers are 9 millimeter, 10 millimeter, .40 SW, .38 special, .44 magnum, .45 ACP, .380 ACP.
50-500 usd
10-200 USD or so
250 or so