Question about .40 S&W and it wearing out guns faster due to high pressure.

GunGuy34

GunGuy34

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The SAAMI pressure limit for the 9×19mm Parabellum is set at 241.32 MPa (35,001 psi) piezo pressure.[19]
The SAAMI pressure limit for the 9×19 mm Parabellum +P is set at 265.45 MPa (38,500 psi) piezo pressure.

The S.A.A.M.I. pressure limit for the .40 S&W is set at 241.32 MPa (35,000 psi), piezo pressure
The .40 S&W works at relatively high pressures 230 MPa (33,000 psi) typical, but 240 MPa (35,000 psi) SAAMI max.


So if both rounds have pretty much the same pressure, why would the .40 wear out a pistol faster then a 9mm? What am i missing? As Ive seen this alot on youtube and have read about it, thus the reason the FBI may switch back to the 9mm.

Im not a reloader either so easy on the nose if im missing something obvious.
 
Total force exerted would be greater with 40 because of greater surface area than 9 at equal pressure.

To have shot IPSC and done 50k + rounds per year, you need to work hard at wearing out a quality gun...unless it's a Norinco...my SIG p226 with 80k that only had recoil spring changes still looked new. My beretta 302, bought used, added another 100k to it in two years, still running...yet other brands aren't as reliable/durable.
 
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Ganderite said:
Called high presure because it and the 9mm are high pressure rounds. Similar pressure to the 357mag.

45ACp and 38 Spl are low pressure loads.
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40 is always singled out as high pressure not the 9mm. just google 40 high pressure and you will see the youtube vids with james yeager and others singling out the 40 as high pressure and saying it wears out guns faster due to that pressure. from what i can find it seems like bs. which is why i asked the question here to see if im missing something.
 
GunGuy34 said:
40 is always singled out as high pressure not the 9mm. just google 40 high pressure and you will see the youtube vids with james yeager and others singling out the 40 as high pressure and saying it wears out guns faster due to that pressure. from what i can find it seems like bs. which is why i asked the question here to see if im missing something.
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Just because they know how to shoot well doesn't necessarily mean that they have a good grasp of how their firearms are engineered or function. ;) As mentioned, many times they are just regurgitating what they have heard/read elsewhere. Instructors are the source of many, many enduring myths. People then to believe them because they are instructors. They are not necessarily experts on gunsmithing, physics, engineering, kinesiology, etc.
 
Chuckbuster said:
An interesting question. I have wondered about that too. I have some Remington small pistol primers that have a warning about using them in high pressure rounds like the .40 and .357. Yet, unless I missed it on the box, 9mm is okay...
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That's an odd warning without explanation. Actually, using smaller primers for higher pressures in bolt action rifles is preferred.
The 9mm is the poor mans .357.
 
krausb said:
Just because they know how to shoot well doesn't necessarily mean that they have a good grasp of how their firearms are engineered or function. ;) As mentioned, many times they are just regurgitating what they have heard/read elsewhere. Instructors are the source of many, many enduring myths. People then to believe them because they are instructors. They are not necessarily experts on gunsmithing, physics, engineering, kinesiology, etc.
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id like to find out where it all started as lots seem to be saying it but it doesnt seem to make sense to me from what ive read.

there was a big thread on here about the fbi switching back to 9mm as 40 was too hard on guns saying it was the high pressure. i dont get it.
 
GunGuy34 said:
id like to find out where it all started as lots seem to be saying it but it doesnt seem to make sense to me from what ive read.

there was a big thread on here about the fbi switching back to 9mm as 40 was too hard on guns saying it was the high pressure. i dont get it.
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I'm speculating here, but I suspect the myth comes from the early days of the .40 S&W cartridge. Many manufacturers were simply re-barreling 9mm guns to make "new" .40 S&W guns without beefing up the designs at all. As pointed out, while the chamber pressures are similar, the energies are different and many of the early .40's on the market could not stand up to the beating. I suppose the simplest way of explaining it was "higher pressure causes more damage" and because the internet loves simple easy to repeat slogans, it stuck. And while not quite accurate, it is close enough to the truth that no one that knew any better bothered to offer a proper explanation...
 
GunGuy34 said:
The SAAMI pressure limit for the 9×19mm Parabellum is set at 241.32 MPa (35,001 psi) piezo pressure.[19]
The SAAMI pressure limit for the 9×19 mm Parabellum +P is set at 265.45 MPa (38,500 psi) piezo pressure.

The S.A.A.M.I. pressure limit for the .40 S&W is set at 241.32 MPa (35,000 psi), piezo pressure
The .40 S&W works at relatively high pressures 230 MPa (33,000 psi) typical, but 240 MPa (35,000 psi) SAAMI max.


So if both rounds have pretty much the same pressure, why would the .40 wear out a pistol faster then a 9mm? What am i missing? As Ive seen this alot on youtube and have read about it, thus the reason the FBI may switch back to the 9mm.

Im not a reloader either so easy on the nose if im missing something obvious.
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Wearing out semi autos would have more to do with having appropriate spring tension for absorbing recoil than chamber pressure. The .40 does have more energy but not huge amounts more. You see way more substantial differences in rifles and they are built heavier for bigger cartridges but only if they are way bigger.
 
bushwhacker said:
The story I remember was about the FBI trying to go to 10mm for stopping power but found the recoil to be too much for many agents to shoot well with.
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Not to mention that the pistols/frames/grips needed to house the 10mm ctg being on the large size for persons with smaller hands.

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NAA.
 
Pistols in my department are 10 years old at least. All chambered in .40. They due for replacement this year, but despite thousands of rounds I can hardly notice any wear. You need A LOT of rounds to wear a decent quality pistol.
 
bushwhacker said:
The story I remember was about the FBI trying to go to 10mm for stopping power but found the recoil to be too much for many agents to shoot well with.
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Yes a .40 is a necked down 10mm but thats not the question that I asked in the beginning. I want to know why so many call the .40 S&W a high pressure round that will wear out guns faster then the 9mm that operates at the same pressure. With modern guns, the springs, supported cases in the barrels ect have been fixed. So why are folks still saying that the .40 S&W is harder on guns?

If people were saying 9mm was cheaper and had more capacity and does pretty much the same thing as .40 s&w then I would agree. Instead they keep calling the .40 a high pressure round thats is hard on guns. I have seen several videos on youtube claiming this, as well as several other forums.

There is also a consencous out there that the FBI is considering switching back to 9mm as .40 was harder on the guns and wore them out faster. I think it would be cause 9mm is cheaper, has more capacity and with todays ammo can do just as good a job. But most still are saying its due to the .40 wearing out the guns faster.
 
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