Why .40 when there is 10mm?

Recoil and penetration.

I'm with you, I'm a relatively big strong guy that has no problem with potent cartridges, but a lot of people do.

Law enforcement agencies rejected it because they have lowered the physical standards of acceptable applicants and some of them can't come back on target quickly enough with a 10mm...plus penetration of this round makes it more of a danger to innocent bystanders.

I think they should eliminate the wimps, and use large expanding hollow points to minimize over penetration, but that is JMHO.

I personally don't have a handgun chambered in 10mm, but would like to get one. Either in semi-auto, or a used revolver.

Blue1

Well, .40 is more available, has less recoil and report, and is still the most common law enforcement caliber in the US.

The .40 isn't a compromise between the 9 and .45 in my opinion. The 10 mm is a fine round. However, I feel that there is room for both it and the .40. After all, the .38 and .357 still sell like gang busters.

Why .40 when there is 10mm?

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Because you don't want to have a huge gun.

In the Glock family, the G22 is much more small hand friendly than the G20 even if it is an SF or Gen 4 version.

If you prefer a 1911, there probably isn't much advantage to getting a .40S&W since the gun is designed for 10MM cartridge length. There is not much advantage to the .40S&W in this case since the gun of choice is already sized for the longer cartridge.

The 40 was created when the Special Agent-in-Charge FBI Firearms Training Unit's John Hall tested 10mm for FBI use. The FBI tests found that the recoil of the 10mm was not optimal for many shooters and that the terminal performance of the round was still sufficient when it was downloaded to a point that the cartridge could be shrunk to fit in the same size handgun frame as a 9mm pistol. This gave the additional benefit that the guns could be made small enough to fit a wider range of shooters.

On a more fundamental level, the point is that few shooters need the additional firepower of 10mm and manufacturers like the round because they can share frames among popular calibers instead of having to retool for each individual caliber in a model.

The only, only reason I own a 10mm is for the possibility of coming across a bear and I'm not 100% confident even the 10mm is the best pistol round for a bear, but the G20 is a good shootin' 10mm and the capacity is somewhat reassuring.

I think a lot of peoples dislike of .40 recoil has a lot to do with the actual pistol used. I had a Glock 23 in .40 that I think is a lot snappier, less pleasant to shoot than a USP in .40, in that it feels about the same as a 9mm.

To each their own, I do own a 10mm but it's not usually one of my go to range guns, but it is fun to shoot.

Because the .40 S&W ( 10mm Kurtz ) will fit in a 9mm size firearm. The 10mm needs a 45 size platform.
I carry a 10mm Glock when flying out in the bush. I had a Delta Elite 30 years ago but I shot it to death.

Get yourself a timer and do Bill Drills with each caliber.

Why .38 Special when there is .357 Maximum?


There are some questions you just have to ask why they were asked.

I can find .40 on the shelf even when things are bad. I can't find 10mms when things are good. I also live in suburbia, where 10mms are not really needed. If I hung out in the Bush I'd consider the 10.

From what I've read there isn't a lot of difference in the effectiveness of any of the rounds mentioned (9mm, .40, .45, 10mm). I'm sure there will be some but I'm just as sure that many people won't be able to keep a 10mm from flipping up off target so much that double taps are a real problem. With a .40 you get the speed of a 9mm and most of the mass of a .45. It is a very good compromise between those rounds. And even a .45 will cause some to lose their target. I don't have trouble with a .45 but I like the capacity of the .40 pistols I see on the market. Very few .45 pistols come close to the capacity of many .40's. My .40 holds 16+1 rounds. My biggest capacity .45 holds 10+1. I know I could go higher but there are things about a .45 round that do cause problems. The round travels too slow for certain situations according to what I've read. I have no way of doing the testing done by others so I pretty much rely on the tests I see and read about. .45 bullets tend to not penetrate windshield glass because of traveling at slower speeds than the .40 or the 9mm for example. Again I haven't done this testing but I've read about it. I love my .45's. There are things they will do that a 9mm won't IMO. But there are things a 9mm will do that a .45 won't too and the .40 seems to do al the things either of those rounds will do. And you don't have the recoil of the 10mm to deal with. I suspect I could handle a 10mm alright. I've never shot one. But I'm a fairly big guy that doesn't have a problem with a .45 at all even using 230 gr. ammo. But the guns on the market dictate a lot of my buying habits. I just don't see a lot of 10mm guns to choose from much less ones that have all the features I want. And the FBI has driven the production of the .40 which means more companies involved. That's always how things work. The government can drive the gun industry because companies want those fat contracts and regular people figure they are getting a well tested platform when they go with the guns and caliber the FBI is using along with countless police departments. And I just don't see a lot departments going with the 10mm. The FBI abandoned it for a reason I'm sure. I tend to trust their judgement until I see a reason not to.

thefamcnaj said:

If I hung out in the Bush I'd consider the 10.

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I have a .44 magnum for that purpose. It's much more powerful and if I have a problem with one of the many local black bears I want something strong enough to do the job.

The 10mm is nearly a dead letter now. The guns are few and all of them pretty enormous. They must be to accommodate the very long 10mm OAL. There are very few choices; you can get a Glock or a 1911, or choose from a smattering of oddball makers. There's not much it does vastly better than a .40 S&W except for hunting where it's legal more places than the smaller .40 cal.

I would love to have an MP5 or UMP in 10mm, or some other carbine. But I can't imagine what use I'd have for a 10mm sidearm. Unless HK chambered the USP or Mk23 in 10mm.

Availability
Cost
Recoil
Overkill for most applications

If you like it, go for it. Sig is bringing out the 220 in 10mm so there's another platform option for you. I'll stick with 9 and 40.

10mm is a great reason to reload your own ammo; factory 10mm is scarce and expensive.

Agree with this. I carry my G29 loaded with Underwood 135 gr Nosler Hollow points at 1600 fps (their #s). The thinking is this bullet at this speed will enter and expand massively, thus remain in the body minimizing over penetration.

To one of the above posters, the 10mm is enjoying its most popularity in 20 yrs right now. There are as many companies making the 10 as there ever has been. As far as size, the difference in the the guns chambered for the 10 and the comparable gun chambered in 40 (ie...glock 20 or glock 22) is negligible. Everybody who says there is no appreciable difference in a 10 vs 40 vs 45 vs 9 vs 357 Sig vs whatever are saying the basic laws of physics don't apply anymore. E=mv2.
Get there fastest with the mostest is an old adage that remains true to this day. The faster you can push a bigger bullet, the more energy. Not that complicated. Bullet design has improved making the 9,40, & 357 Sig more effective than earlier, but those same design improvements apply to the 10 & 45.

Because recoil makes follow-up shots slower and you don't usually need the extra power.

Heck I'm not really recoil-shy for just going out and shooting a few rounds for fun, but if I'm trying to get as many shots on target as quickly as possible I'll even forgo .40 in favor of 9mm.

I have small hands and my first pistol I purchased was a Glock 20C. Love it. I started reloading because 10mm was getting way too expensive to shoot. I like the idea of having near-.357mag power in a 10+ round auto.

Jorzac said:

To one of the above posters, the 10mm is enjoying its most popularity in 20 yrs right now. There are as many companies making the 10 as there ever has been. As far as size, the difference in the the guns chambered for the 10 and the comparable gun chambered in 40 (ie...glock 20 or glock 22) is negligible. Everybody who says there is no appreciable difference in a 10 vs 40 vs 45 vs 9 vs 357 Sig vs whatever are saying the basic laws of physics don't apply anymore. E=mv2.
Get there fastest with the mostest is an old adage that remains true to this day. The faster you can push a bigger bullet, the more energy. Not that complicated. Bullet design has improved making the 9,40, & 357 Sig more effective than earlier, but those same design improvements apply to the 10 & 45.

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I think you should do a little studying of exterior and terminal ballistics. You posted an erroneous formula for calculating Energy (E=mv2). Your assumption that more energy is always better when it comes to SD pistols is also erroneous.

I have a G20. Unless I am going out in the boonies where there are bears that will eat me, I carry a much small pistol that has less but more than sufficient muzzle energy. The only advantage the 10mm gives me in the boonies is greater penetration with heavier bullets when defending against an animal much tougher than any man. I carry the G20 instead of a .44mag because even in the boonies of Arizona you are more likely to need to defend against humans than four legged predators and it has a similar manual of arms to my routinely carried SD pistols. In a SD situation rapidity of fire is faster with a .40 than a 10mm. That is very important to remember because rapidity of hits on an armed human assailant with a sufficiently powerful pistol is more important than making slower hits that have insignificantly greater KE. No 10mm load will ever generate the rifle like energy figures needed to make it a better SD round against humans than a .40.

I think most folks touched on it: The size of the gun (due to OAL), recoil, some folks don't reload, etc.
Oh, and for LOTS of us revolvers cover much of the same ground as a 10mm would.

I say shoot them all and enjoy them all. I use 357 SIG for hiking up in the mountains locally. Love the 10mm, though!

Their has yet to be the ONE caliber to rule them all. That's why there are so many.

I think most folks touched on it: The size of the gun (due to OAL), recoil, some folks don't reload, etc.

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And if you do reload, don't forget the violent ejection -- where I shoot I'm doing great to find half of my brass since it flies well off the beaten path into the weeds

Get yourself a timer and do Bill Drills with each caliber.

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This will truly cause you to understand why its not more popular.

1. I did misstate the formula for energy; I stated mass x velocity squared, its actually 1/2 mass x velocity squared. Fact remains the same: more mass going faster = more energy.
2. Revolvers are fine for the energy part but they fall far short on capacity and speed. So they don't really compare with autos. They're great for what they are, but not the same.
3.10mm doesn't recoil anymore than a 45, and you seldom hear people complain about the recoil of the 45. Everybody should shoot the caliber/pistol combo that allows them to put as many of the most effective bullets that they can safely do so.
4. A lot of the people that weigh in on the 10mm, are doing so based on heresy and internet rumor with no real time actually shooting them.

delete double

why 40?

Uhhh...capacity.

And you dont have to be a 6'6' NBA power forward with large extremities to be able to hold the 40 while firing

Ammo is plentiful.

Better for the recoil averse. Not everyone likes jacked up 10mm loads.

And probably a lot of other reasons.

10mm doesn't recoil anymore than a 45

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Huh?

Recoil depends on momentum. My Delta Elite has a lot more felt recoil than does my Government model.

A 200 grain 10mm will typically be ~1100 fps while a 200gr .45 will be ~950, this is ~16% more momentum (recoil) ignoring the recoil factor of the burning powder which is also higher for the 10mm.

Plugin the data for you favorite loads and you'll see the recoil of .40S&W is about the same as the .45ACP and 10mm is significantly more than either.