.40 s&w

[AdamM]

What is the reason for most (if not all) .40 ammo being flat nosed? I mean other than HP (obviously) every .40 round Ive seen has been a flat nose. 9mm is round, .45 is round and then .40 is flat

[Ballistic043]

mmmm

i think it has something to do with how it feeds to the feed ramp and keeping an overall size similar to 9mm or something like that

[sorensen440]

I have no idea but your right all the stuff I have is flat nosed or hp

[Slayer]

It was designed to fit in a slimmer gripped pistol. It is basically 10mm jr, and the 10mm was only found in larger framed pistols.

[aca72]

http://www.thefiringline.com/forums/showthread.php?p=3100258

[Beelzy]

That flat spot, known as the bullet's Meplat is an enhancement to the bullet
to aid in making a bigger cleaner hole.

It was all the rage with the old Elmer Keith crowd that hunted with handguns
"back in the day"

The second benefit is to aid feeding reliability in all the crappy pistols that
are chambered for the round.

[AdamM]

That flat spot, known as the bullet's Meplat is an enhancement to the bullet
to aid in making a bigger cleaner hole.

It was all the rage with the old Elmer Keith crowd that hunted with handguns
"back in the day"

The second benefit is to aid feeding reliability in all the crappy pistols that
are chambered for the round.

But why is it only .40 that seems to always be flat? I dont think Ive ever even seen a .40 that was round, yet Ive seen other calibers that you can get either round or flat

[Slayer]

That flat spot, known as the bullet's Meplat is an enhancement to the bullet
to aid in making a bigger cleaner hole.

It was all the rage with the old Elmer Keith crowd that hunted with handguns
"back in the day"

The second benefit is to aid feeding reliability in all the crappy pistols that
are chambered for the round.

The FBI wanted a round that was "similar" to the 10mm but with lower recoil and could be chambered in a smaller framed pistol...the flat nose aids in it being able to be chambered in the same frame as a 9mm pistol. Dont know how a flat nose would help create "a bigger cleaner hole".

[basskisser2002]

Your answer

This was taken from a Genitron review of the WSmith M&P40:

The caliber -
The .40 Caliber Smith & Wesson (S&W) cartridge was developed as a joint venture between Winchester and Smith & Wesson in 1989. It was an effort to to create a cartridge with the same power as the 10mm Norma round that the FBI had just started using, but in a shorter case. The shorter cartridge would facilitate accuracy and allow use of a smaller, more comfortable grip frame. The .40 S&W has become the cartridge of choice for many law enforcement agencies in the United States. Typical bullet weight for this cartridge ranges from 135 to 180 grains with an average muzzle energy that approaches 500 ft-lbs.

The following data set is based on standard factory loaded cartridges fired from a 4" barrel, listed by weight, brand, type and muzzle velocity. This is only a very small sample of what is available.

135 grain Federal JHP : 1,190 Feet Per Second
155 grain Hornady JHP : 1,180 Feet Per Second
165 grain Winchester FMJ: 1,060 Feet Per Second
180 grain CCI-Speer JHP: 1,025 Feet Per Second

[AdamM]

The FBI wanted a round that was "similar" to the 10mm but with lower recoil and could be chambered in a smaller framed pistol
Yea I read the same thing.. happened after the '86 FBI shootout where 2 agents got killed I believe
...the flat nose aids in it being able to be chambered in the same frame as a 9mm pistol
Makes sense, shorter round is equivilent to 9mm length, diameter really doesnt matter, just changes amount of rounds that the mag can hold.
Dont know how a flat nose would help create "a bigger cleaner hole".
Kinda how wadcutters are. Sorta

Bold

[Slayer]

Bold

Basskisser's post pretty much says what I did, but in fancy article copy and paste form.

...oh heres more trivia for you: The first .40 S&W gun wasn't even a S&W. The Glock 22 was the first chambered in .40 S&W.

[AdamM]

Basskisser's post pretty much says what I did, but in fancy article copy and paste form.

...oh heres more trivia for you: The first .40 S&W gun wasn't even a S&W. The Glock 22 was the first chambered in .40 S&W.

Haha, reminds me of a post I read somewhere a while ago (Probably on here) when someone asked "does .357SIG come in anything other than Glocks?" haha

[sargenv]

I wondered that myself for some time. There are a few RN bullets available for the 40 S&W but not many.. I can think of 4 right off the bat.. 155 gr Lead RN by Redline bullets, 155 gr HBRN by Berry's, 180 gr RN by Billy Bullets, and 140 gr RN by Bear creek..

Otherwise they are truncated cones, HP's, or RNFP's.

[AdamM]

I wondered that myself for some time. There are a few RN bullets available for the 40 S&W but not many.. I can think of 4 right off the bat.. 155 gr Lead RN by Redline bullets, 155 gr HBRN by Berry's, 180 gr RN by Billy Bullets, and 140 gr RN by Bear creek..

Otherwise they are truncated cones, HP's, or RNFP's.

Do you have any experience with any of these? If so, how do they feed?

[buffybuster]

The 40SW is primarily loaded with a truncated cone/RNFP type of bullet (similar in profile to the HP's available at the time) for ONE reason, which is to keep the OAL within the 9x19 envelop.

Smith&Wesson developed the 40SW after getting the FBI contract for the 10mmAuto. The FBI's plan was agents carry pistols with 180gr@950fps (reduce recoil) and also have access to MP10 carbines with fullpower 180g@1300fps and in a pinch they could share ammo.

S&W realized that they could shorten the case enough to fit their 9x19 frame/mags and still meet the 180gr@950fps performance target. In essence S&W reinvented the 41AE. The truncated cone was chosen to keep the OAL of the 40SW cartridge within the standard magazine dimensions with a 180gr bullet and leave enough case capacity for the powder. If a RN bullet is used the bullet would have to be seated deeper which could begin to push the ogive of the bullet below the casemouth which could introduce bullet setback (bad) and would also intrude on case capacity (bad). S&W also changed from a Large Primer to a Small Primer (good). This allowed S&W to market their standard frame pistols to a mass market. Soon thereafter, the FBI dropped the 10mmAuto and went to the 40SW.

The irony was that Glock was able to get a hold of some 40SW prototype cases somehow and they beat S&W to the market by introducing the M22 before S&W brought out the 4006.