40 vs. 45

[45user]

I currently do not own 40 caliber handguns and am looking into buy a S&W MP in either 9mm or 45 because that's the calibers that I already shoot. However I'd like to find out more about 40 S&W. How do they shoot compare to 9mm and 45acp? What about stopping power? Reloading data? I guess I am asking generally what are the pros and cons of 40 calibers?
Thank you for your help in advance!
45

[knucklehead0202]

40 is better than 9, a little snappier recoil, but just as accurate if you get used to it, but not as powerful as 45. 45's have a heavier, but less jumpy kind of recoil. more of a push that a hop, if you catch my meaning. you'd really have to try them to know for sure what works for you. i prefer a 45 or .38/357 myself. accuracy, stopping power, and reasonable, managable recoil. but everyone works differently.

[caoboy]

http://www.calguns.net/calgunforum/showthread.php?t=287443

[Doheny]

It's all been said before, but IMHO, .40 is pretty snappy and of course costs more than 9mm. You can get some pretty hot 9mm rounds that will certainly leave a mark if you hit somebody with them.

I wouldn't lose any sleep if I had to depend on a 9mm for a HD platform. With that said, I only own .40 and .45. I'm starting to look for a 9mm.

[randy]

40 is a great caliber but in this state 45 is the way to go. The big deal for the 40 is hi cap with close to 45 stopping power. Since you can only have 10 rounds then why not stick with 45.

That being said I shoot 40 and 9 because I'm old and a gamer. Old means I have fat mags.

[TestPilot]

From Wikipedia: Go HERE for full story.
The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the FBI's reduced velocity 10mm cartridge which could be retrofitted into medium-frame (9mm size) automatic handguns.
The .40 S&W was originally loaded at subsonic velocity (around 980 fps) with a 180 grain bullet. Since its introduction, various loads have been created, with the majority being either 155, 165 or 180 grain. However, there are some bullets with weights as light as 135 grain and as heavy as 200 grain. Cor-Bon offer a 135 grain JHP as well as a 140 grain Barnes XPB hollow-point. Double Tap Ammo, based out of Cedar City, Utah loads a 135gr Nosler JHP, a 155gr, 165gr and 180gr Speer Gold Dot hollow-point (marketed as "Bonded Defense"), a 180gr Hornady XTP JHP, and three different 200gr loads included a 200gr Full Metal Jacket (FMJ), a 200gr Hornady XTP JHP and Double Tap's own 200gr WFNGC (Wide Flat Nose Gas check) hard cast lead bullet; the latter specifically designed for hunting and woods carry applications.
The .40 S&W has been noted in a number of cartridge case failures, particularly in older Glock pistols due to the relatively large area of unsupported case head in those barrels, given its high working pressure.[30] The feed ramp on the Glock .40 S&W pistols are larger than normal, which leaves the rear bottom of the case unsupported, and it is in this unsupported area that the cases fail. Most, but not all, of the failures have occurred with reloaded or remanufactured ammunition. Cartridges loaded at or above the SAAMI pressure, or slightly oversized cases which fire slightly out of battery are often considered to be the cause of these failures. These failures are referred to by many as "kaBooms" or "kB!" for short. While these case failures do not often injure the person holding the pistol, the venting of high pressure gas tends to eject the magazine out of the magazine well in a spectacular fashion, and usually destroys the pistol. In some cases, the barrel will also fail, blowing the top of the chamber off.

While the .40 S&W is far from the only cartridge to suffer from case failures, it is more susceptible for a number of reasons. The .40 S&W works at fairly high pressures (33,000 psi/230 MPa typical, but 35,000 psi/240 MPa SAAMI max) for a large caliber handgun cartridge, significantly more than, say, the .45 ACP.[31] Since the .40 S&W is a wide cartridge for its length, and is often adapted to frames designed for the equally long but narrower 9x19mm cartridge, the length of the feed ramp must be longer to provide the same angle, which causes the feed ramp to extend into the chamber. This in turn leaves more of the case head unsupported. While this is not necessarily unsafe, it does reduce the margin of safety. When exacerbated by out of battery firing (leaving even more case head exposed) and potentially weakened brass (due to reloading) these factors appear to lead to the higher incidents of chamber failure. The number of case failures in the .40 S&W is serious enough that Accurate Arms no longer recommends reloading of .40 S&W cartridges for firearms without complete case head support

[J-cat]

but not as powerful as 45.

How is it not as powerful? How are you measuring "power" ?

[mif_slim]

40 is a good round. I've owned 25auto, 380's, 9mm, 40s and 45s before but I perfer the 40 more just because I like the feel of it more. At the time of my purchase, 9mm wasnt worth reloading and 45 was expensive so I got the 40 to be in the middle (BlazerBrass was going for 9.97 or something at the time) and I kept all the brass for reloading (that was years ago and Im still using some of the same batch of brass from those days). It comes out to about .09 per round (free bullets). But if you can man up, the 40 is just as good as the .45 in penetration data. The only one that is diffrent is the 10mm compared to the 9,40 & 45.

[bfoosh006]

IMHO, the Forty is better then the Nine and the .45 is better then the Forty.
Now,.. I have no data to support that belief..but, common sense will tell you a bigger bullet, (9 v. 40,size and weight) at the same speeds should perform better. And as for the .45, its bulk at relatively low pressure, has big benefits.

[rockdogz]

IMHO, the Forty is better then the Nine and the .45 is better then the Forty.
Now,.. I have no data to support that belief..but, common sense will tell you a bigger bullet, (9 v. 40,size and weight) at the same speeds should perform better. And as for the .45, its bulk at relatively low pressure, has big benefits.

Sounds reasonable, except that the .40 is generally going a bit faster than the .45 unless you talk about the +P loads.

[fermi]

I have a .40.

The recoil on a .40 is no big deal, I dont notice it much at all compared to shooting 9 mm.

[biofire]

It's the round, not the caliber...

In terms of tissue damage inflicted, the type of round is more important than the caliber. Modern computers and ballistics technology have allowed engineers to design "man stoppers" in 9 mm and up. Prior to modern ballistics, the belief was that bigger rounds are better, and it was true back then. But now, it really is about the type of round and not the caliber anymore.

If you don't believe it, read "Stopping Power" by Marshall and Sanow.

As always, shoot a caliber that feels right to you. I'm much more accurate with my 45 ACP than I am with my 9 mm. Not sure why, but its probably because it fits my hands better.