there's a whole bunch of nicely built pistols chambered in 40 S&W

[Grumpy]

there's a whole bunch of nicely built, and well known brands of pistols chambered in 40 S&W, similar in size to the popular 9mm handguns,
the 40 S&W is an effective defensive cartridge, having more potential power than your typical 9MM with only a slight reduction in magazine capacity
and some 10mm ammo is loaded down to nearly similar ballistics,
after the FBI lost a couple agents in a shootout where the handguns they used failed to rapidly stop a couple bank robbers , the FBI decided they needed a more effective handgun, they swapped for a brief time to the 10mm but found agents who were not all that skilled were intimidated ,
by the louder muzzle blast and increased recoil so they ask the ammo company's to reduce the cartridge power a bit, the handgun manufacturers
developed the 40 S&W (many agents called it the (40 SHORT AND WEAK) that could be used in what was basically the same frame size as the 9mm para cartridge.
but the 40 S&W was only marginally more powerful than the hotter 9mm ammo, as a result.

1986 FBI Miami shootout - Wikipedia

en.wikipedia.org

An Official Journal Of The NRA | A History Of FBI Handguns

The FBI has issued a wide variety of handguns to its agents over the years.

www.americanrifleman.org

The Reasons Why FBI Went Back to 9mm

The FBI has selected Glock Gen 5 handguns in 9mm as their service weapon. There has been much speculation about the reasons for their caliber change.

sofrep.com

keep in mind its shot placement and the projectile design that matters more than the cartridge power level,
but having a bit more muzzle energy certainly never hurts.

U.S. Government Handguns: Who Carries What?

• FBI: Glock 17 & Glock 19. ...
• CIA: Glock 19 & SIG Sauer P226. ...
• U.S. Secret Service: SIG Sauer P229 DAK and Glock 19. ...
• U.S. Army: Beretta M9 and SIG Sauer M17. ...
• U.S. Navy: Beretta M9, SIG Sauer M11, and M18. ...
• U.S. Air Force: Beretta M9, SIG P226, and M18. ...
• U.S. Marine Corps: Sig M18.

Handgun Self-Defense Ammunition - Ballistic Testing Data

Lucky Gunner tests more than 110 different 9mm, 45 ACP, 40 S&W and 380 ACP handgun self-defense ammunition loads in ballistic gel with analysis and video.

www.luckygunner.com

 

[Grumpy]

personally I think the S&W 1006 was and is an excellent well made and very accurate 10mm hand gun

 

[rlphvac]

I'm not to crazy about the 40 S&W after I damaged a nice CZ pistol on the first shot out of a brand new gun at the time all I bought was 40 S&W but converted the ones I could to 9mm and selling off some to replace them with 9mm. How I damaged the gun and I was lucky not my hand was because of the Glock bulge. I am real careful reloading the 40 now more than I was at the time and anything run through a Glock is kept separate and there should be more info about the Glock bulge

 

[Grumpy]

for those that have no idea as to what he's referring too, and I bet its a significant percentage of newer guys.
glock and many other pistols have feed ramps that are designed to allow slightly over size cartridge case dimensions to easily chamber,
but that leaves the rear of the case a bit less supported in the chamber over the feed ramp, now a cartridge case expands on firing , it swells to the chamber dimensions to seal the pressure in the guns chamber, but brass will only expand a very small percentage of its original diameter
and seal the chamber before it weakens if its not supported along the whole outer chamber, glocks have very good reliability and this in part is the result of having a moderately loose chamber that allows almost any cartridge case to easily chamber, but the combo of the area over the feed ramp and loose chamber tolerance's results in the unsupported case head area n, flexing or swelling and potentially failing or rupturing as the tens of thousands of pounds per square inch of pressure seals the chamber, the unsupported area over the feed ramp bursts, or ruptures as its not fully supported due the cartridge case not being fully supported in the area over the feed ramp at the rear of the cartridge case when the case is fully seated in the chamber, notice in the picture below the area over the feed ramp has been re designed several times to get better(more fully supported ) around the cartridge case rear over the feed ramp.
a factory brass case expanded like that will frequently fail if reloaded, as the brass was significantly weakened, and when resized and when reloaded its not nearly as strong as it was originally , especially if the same unsupported area is over the feed ramp on the second firing.
now almost all semi auto handguns will have some degree of loose chambers and this is why brass is resized during the reloading process, as theres always some variation in even factory cartridge dimensions thus the need for a slightly larger chamber that the cartridge dimensions but ideally the chamber will be just large enough to chamber the average or slightly larger factory cartridge case , but to enhance reliability and to ensure all factory ammo, even reloaded improperly ammo chambers GLOCK chambers are a bit larger,
(notice the warning on all glock factory boxes to (NEVER USE HANDLOADS) this is GLOCK trying to reduce problems as most factory ammo is intentionally manufactured on or too, the smaller diameter range to help insure better reliability and better feed consistency, match the smaller case to a noticeably larger chamber and feed and function tends to be very reliable, but brass should not be reloaded from that combo!
another reason the factory glock barrel is polygonal rifling this does not give ideal accuracy with soft lead bullets some reloaders prefer.
glocks tend to work well with factory ammo and jacketed bullets, but a reloaded case and lead bullets, especially at higher camber pressures can result in less reliability of damage to the gun

You are being redirected...

Glock Talk

A forum community dedicated to Glock firearm owners and enthusiasts. Come join the discussion about optics, gunsmithing, styles, reviews, troubleshooting, accessories, classifieds, and more!

www.glocktalk.com

 

[rlphvac]

First off thank you Grumpy, you explained that better than I ever could and I really want people to understand what happens when you load for the 40 S&W and the fact that I was very very luckey, I could have lost my right hand. I never knew about the bulge until it after the accident that I had

 

[Grumpy]

I'm glad you did not lose a few fingers,
and you just lost some money
(the cost of the handgun) but you gained some knowledge
btw that's why almost all of the really high pressure handgun cartridges,
like the 454 casull,(65,000 psi and 500 S&W mag (60,000 psi) 480 ruger (48,000 psi) yes there are other high pressure cartridges
are designed for use in revolvers,or single shot break action, or bolt action pistols as the case is fully supported

Max Chamber Pressure - SAAMI Specs

 

[rlphvac]

I learned a lot about supported chambers since that time and I also heard that there was never a true 40 gun made that the manufacture's just punched out a 9mm to a 40 S&W and I do believe this because through the years I have had more than a few 9mm and 40 S&W that every part interchanged between the guns