"high pressure" pistol cartridges

[ArgyleAdams]

Though I don't remember seeing anything about this previously, in the past two days I have happened upon a handful of discussions (weird how stuff like this seems to come in groups) on the wear-and-tear that different cartridges put on pistols (specifically autoloaders). They all go like this:

Modern, high pressure cartridges like the .40S&W will wear out a gun faster than "standard" (or "low pressure") cartridges like 9x19 or .45 ACP.

Now, I did a little research (SAAMI specs), and while the .45 ACP is indeed a lower pressure round (at 21000 PSI), both the 9x19 and .40S&W have the exact same spec at 35000 PSI. Why then are people calling .40 "high pressure" and, in the same breath, saying that a round that "isn't" "high pressure" (9mm) is a better choice for firearm longevity?

Is this some kind of superstition, something that's been repeated enough that it's dogma? I could see the .40 causing more damage than the 9mm over time as a more powerful cartridge (it has a greater case capacity by about 45%, so burns more propellant). This, however, has to do with the energy released upon firing, not with the pressure difference (of which there is none).

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[oli700]

Why then are people calling .40 "high pressure" and, in the same breath, saying that a round that "isn't" "high pressure" (9mm) is a better choice for firearm longevity?

They simply don't know what they are talking about. I was going to correct you on 9mm but as I read further, I see you have done all your own leg work, bravo

 

[metrotps]

The misconception about pressure may come from reports that .40 S&W is harder on barrels and on frames than a 9x19 since many pistols use similar frames, slides, etc. Whether this is true is still under investigation but there seems to be more throat erosion with the .40 just like the case of the 125 grain JHP bullet in the .357 Magnum with forcing cone cracking. The .40 S&W shoots a heavier bullet also, with the increased powder, and this might fuel some ideas that it's "high pressure" vs the 9MM. I have a friend that shot in excess of 250,000 rounds of 9MM through his 6906 S&W before the frame cracked and he sent it back to S&W. They replaced most of the pistol and only charged him $250. I know a lot of Glock people that shoot .40 S&W but they have nowhere near that round count.

 

[Mark W.]

Also something to keep in mind when it comes to barrels Is that between 9mm and .40 if used in the same pistol with the same barrel exterior dimensions the .40 will heat up the barrel faster and to a higher final temp. Due to there being less mass in the barrel to disapate the heat. Add to this that a .40 for the same pressure level uses more powder you have more heat generated.

To what degree this effects wear and tear on the barrel I don't know but it is a factor to consider.

 

[Don H]

Though I don't remember seeing anything about this previously, in the past two days I have happened upon a handful of discussions (weird how stuff like this seems to come in groups) on the wear-and-tear that different cartridges put on pistols (specifically autoloaders). They all go like this:.

Could it be because of this 'expert'?

 

[mkwerx]

There is plenty of evidence out there of the .40SW and the .357Sig wearing guns out faster than 9mm in the same platform. The SAAMI pressure doesn't really come in to play - but the .40SW does have more recoil than a 9x19, as does the .357Sig. More energy is getting exerted on the gun by those cartridges - so they'll wear an otherwise identical gun out quicker than their 9mm counterpart. It's like shooting full house 10mm vs standard loaded .45 in the same platform - which is going to wear the gun out faster?

 

[Cypress]

Just a guess, but this may be the fallout from the rumored .40 S&W Glock kb's. 180gr lead bullets in a polygonal bbl + non-fully supported chambers = boomsky.

There are many theories as to why the .40 S&W explodes more, and instead of doing anything scientific, people continue to ramble on about "higher pressure cartridges".

One thing remains true: A .40 S&W bullet that has been seated too deeply within the brass (or pushed in from repeatedly chambering the round) can be a disaster waiting to happen. When I shot .40 (several Glock 22's) I would check all of my rounds for OAL. Only found one factory round that was seated incorrectly, but it was seated deep enough to more than triple the internal pressure (!!!!!)

 

[the4thshake]

How many people here have actually worn any gun out?

 

[TAD]

How many people here have actually worn any gun out?

I have taken some of my guns out of the safe thousands of times. Starting to show a lot of wear. If I take them out 500-1000 times more I believe they will be worn out. Mind you I dont shoot them just take them out to fondle them.

So I have almost wore out about 6 of my favorites. The other 20 are fine and show no signs of wearing out.

 

[Mark W.]

I'm owned a Winchester model 1906 Gallery model .22 that had been shot so many times the butt stock had a pronounced sway back from all the cheeks resting on it. It had I am sure been an actual shooting gallery rifle. The outside had only brownish patina on it. The barrel looked like a metal garbage can on the inside. You still got a hint of twist but you couldn't actually see any rifling. The little thing functioned like a dream and wiuld alternately fire shorts long and long rifles as fast as you could beat that pump.

And it would skip a pop can around the range all day long at 75 yards with cheap .22LR

I'm guessing that 100 year old rifle had fired more round then any modern pistol not used in some sort of factory test.

I sold it to a young man (aged 11) and his dad who relined the barrel reblued the metal and replaced the butt stock and pump. They showed it to me later and it looked like a 10 year old gun that was well taken care of and the little guy whos rifle it was couldn't have prouder.

Wear out a gun sure I guess it could be done.

 

[Silver Hand]

How many people here have actually worn any gun out?

I have no safe queens and have shot out several hand guns and wore down hard a few rifle barrels in my life time.
Auto loaders- When I load for pinking I apply just enough powder in the cartridge case to work the action= low pressure.
Knowing the gun, when I load for defense 'Full House loads' I apply what the cartridge will withstand by reading the warning signs of hi pressure.
I have seen permanent damage or ware that included metal movement from hi pressure loads in as little as five rounds in guns other than my own.
Caliber has nothing to do with it. Not shooting modern hi pressure ammunition in Older Pistols might be a good Idea. Some just won't hold up to it. You will shoot them out fairly quickly. Same with older rifles, Early 30-06 Springfield for instance.

 

[mkwerx]

How many people here have actually worn any gun out?

I found out that WCSO is ditching their .40 caliber Glocks because they were seeing accelerated wear and breakage issues. They're sticking with .45's and 9x19.

Seattle PD also had issues wearing out their .40 caliber Glocks. They probably aren't shooting these guns anymore than most motivated shooters would shoot theirs - few hundred rounds at a time, a few thousand rounds a year.

 

[clambo]

You were misinformed. After last week's shooting debacle it was decided to disarm WCSO and send them to London to be trained as bobbies....no, wait, they were sent to the Reno Sheriff's Dept. for remedial comedy training.

 

[mkwerx]

You were misinformed. After last week's shooting debacle it was decided to disarm WCSO and send them to London to be trained as bobbies....no, wait, they were sent to the Reno Sheriff's Dept. for remedial comedy training.

That's funny right there. I think it's going to be pretty interesting to see what happens if the dispatch logs for that call get made public.