Firing .40 in a Glock 10mm.

I bought a police surplus 1006 a few years ago, and at that time, had a hard time finding 10mm.
Read a magazine review of the 1006 which mentioned that they shot 40s&w in it with no problems.
So, I tried it.
I also had no problem, and ended up shooting a couple hundred rounds through my 1006.
 
What is the purpose in buying a gun that fires a caliber different then the one you will commonly use? I guess I am back to the "why" factor. If you want to shoot .40 there are many nice .40s out there to chose from.
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This is a valid question and for me, it's extremely easy to answer:

For many years, 10mm was my choice for daily carry and regular practice with it is an important part of my routine (and for many or most who carry) and as are most 10mm fans, handloading is the way to go. As such, the 10mm brass is very important. You don't just "find" the stuff scattered anywhere and everywhere and it's odd enough that you also rarely see bags of used 10mm brass offered for sale.

.40 S&W brass is on the far, FAR other end of the spectrum. Next to 9mm brass, it's easily the MOST plentiful stuff on this planet. It's scattered everywhere and even many .40cal handloaders don't bend over backwards to pick the stuff up.

So wanting to run a favorite 10mm pistol with .40cal brass is almost a natural inclination for any 10mm fan, and we know going in that YES, it's not shooting exactly 10mm loads, but it still offers a lot of repetition and practice with the handgun itself, something that isn't replicated quite as well with a whole different handgun, especially when you are talking about a carry gun, a holster for it, etc etc.

Furthermore, especially for some of us who are long students of handloading and internal ballistics... .40cal specifically brings a different thought process to the load bench because it's early history was inundated with "over-pressure events" and problems associated with the cartridge itself and as much/more the platforms built for it. This subject takes off on a tangent very much away from the original topic, but it's absolutely relevant for some of us and the bottom line of it is... .40 S&W run from a 10mm pistol (rather than a .40 S&W pistol) is a fantastic idea if that's what you wish to do. Most/many .40cal pistols began life as 9mm guns adapted for a larger round, where 10mm pistols typically started life as .45cal-sized guns that were adapted for a smaller-diameter round.

Me, I carried a Glock 29 for more than 7 years and have run over 6,500 rounds through it. I bought a KKM .40 S&W barrel for it to handle .40cal ammo and my log reflects that 3,400 have been 10mm through the OEM barrel and 3,100 have been .40cal through the KKM barrel.

So to answer the quoted question, oh YES there are great reasons to buy any particular guns, even if it doesn't seem to occur to you quickly.

To answer the OP, I don't believe there is much of a safety risk in shooting .40cal ammo in Glock 10mm pistols, or in any 10mm pistols. However, I don't think it's a favor to the pistol, especially the extractor, and I won't do it. However, if I were going to do it, I think Glock is the best platform for it simply because Glock pistols are ugly, soulless, easily replaceable, easy to get parts for, and Glock pistols are extremely durable and a very good defense against poor use, bad practices, neglect and abuse.

I won't do it in any of my 10mm pistols, but you can bet your life I will never do it in my Smith & Wesson 1006.
 
I get the idea - I have a 10MM and have no ammo available so I'm going to shoot .40. But these people shooting thousands of rounds in competition... why did they not buy a dedicated .40 platform?
 
10mm gun is usually a larger, heavier gun. Better for shooting in nearly every way than a similar gun that is smaller, lighter and shorter. This is not difficult to see.

And sometimes, it's not about what someone buys specifically for a task, but rather how they can use something they already have for a specific task.
 
10mm gun is usually a larger, heavier gun. Better for shooting in nearly every way than a similar gun that is smaller, lighter and shorter.
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That's a sweeping generalization isn't it? Is the larger heavier gun always better for shooting? What kinda shooting are you speaking of? Is it better for carrying 8-12 hours a day? What are you using the gun for? What's it's purpose? If so why not buy a all steel 40 S&W piece if you wish to shoot 40 S&W from a heavier piece?

Why not switch the 10mm barrel in a Glock for a 40 barrel and make the other adjustments needed?

Would you suggest that law enforcement begin to carry guns built for 10mm but load them with 40 S&W? If not why not?

tipoc
 
Used by thousands in pistol comps? I don't understand how 40 S&W used routinely in a 10mm chambered barrel could yield consistent results--by definition the case is not headspacing properly in a reliably repeatable manner I would think, no? someone please explain. : )
 
tipoc said:
It can be done. Main question is why you would do it other than in an emergency.
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If it can be done, it will be done. No reason or logic necessary.

We have a member at one range who shows up about every other month and shoots .40 S&W's out of an extremely nice original WW2 1911. About once per magazine the next round will jump the mag lips and shoot out the ejection port with the just-fired brass.

It seems to work fine except for the funny looking brass (I guess they would be called fire-formed 40-45's) and unfired rounds that jumped the mag lips lying around.

I have no clue why he does it, not like he's trying to save money on ammo. He's an orthopedic surgeon.
 
I always thought a Medusa revolver would be fun. Just toss a bunch of .380, 9MM, 357, 38 and various other rounds in a big box and randomly feed them in at the range. Watch the people in the stalls next to you move over.
 
Seems to me a barrel in 40 S&W is in order. No problems firing 38s in a 357, that rim keeps the round secure. There was a writer in Guns and Ammo who found firing 9MMs out of a 38 Super was a simple matter of a replacement barrel and magazine.
 
If it can be done, it will be done. No reason or logic necessary.
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There's always a reason. If not it wouldn't be done in the first place. The reason may be to see if it can be done and what the results will be once it is done. But after that...why keep on with it?

There's a reason. Some folks enjoy doing odd things and that's the reason. Nope there's always a reason...just sometimes not a good one.

We have a member at one range who shows up about every other month and shoots .40 S&W's out of an extremely nice original WW2 1911. About once per magazine the next round will jump the mag lips and shoot out the ejection port with the just-fired brass.

It seems to work fine except for the funny looking brass (I guess they would be called fire-formed 40-45's) and unfired rounds that jumped the mag lips lying around.

I have no clue why he does it, not like he's trying to save money on ammo. He's an orthopedic surgeon.
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You have no clue why he does it, so ask him. Then you'll have a clue.

Meanwhile...here...https://www.youtube.com/watch?v=eE5trZ8VD-k

Like here I'm asking...would a fella recommend that a law enforcement agency switch to 10mm handguns but load them with 40 S&W? If so why and if not why not?

tipoc
 
tipoc, yours is the "sweeping generalization." I was answering directly the question of why someone might compete with .40cal ammo in a 10mm-sized handgun. Not for half a day, every day carry, not for LE duty, not for under the pillow and not for ankle carry while competing in the 100-yard dash.

For competition shooting.

I handed my stock G29 with 180gr@1,110fps handloads to a very competitive and talented local competitor and he handed back after firing 6 or 7 from the 10-rd mag. He didn't care for it but thanked me for the trial. His competition gun at that time was a Glock 20 with a .40 S&W conversion barrel, running .40cal ammo.
 
Thank you Sevens. But you didn't explain that to begin with.

But you point out something important...

I handed my stock G29 with 180gr@1,110fps handloads to a very competitive and talented local competitor and he handed back after firing 6 or 7 from the 10-rd mag. He didn't care for it but thanked me for the trial. His competition gun at that time was a Glock 20 with a .40 S&W conversion barrel, running .40cal ammo.
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He was running his G20 with a 40 S&W conversion barrel in it and not a stock G20 with a 10mm barrel running 40 S&W ammo in it for competition. The issue in this thread is running 40 S&W through a 10mm barrel, not in emergency or for the odd shot but as a steady diet, for everyday carry, for competition, for crisis situations.

If you do, do it, do you recommend others do it? Cuz as the op considers, it's just as reliable and safe as running 40 S&W through a 40 S&W barrel.

tipoc
 
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laytonj1: said:
...You have to use moon clips to properly headspace the 40 S&W cartridges (with a S&W 610 revolver).
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The same moon clips work with both .40 S&W and 10mm with the S&W 610 revolver. Firing 10MM doesn’t necessarily require the use of moon clips, although you would need to use a wood dowel rod to push the spent 10mm casings out of the cylinder, while moon clips must be used with .40 S&W.
 
I have done enough research on this subject, through the use of the internet, to know that there are a lot more shooters than I can count firing .40 (hundreds of rounds in most cases, thousands in others) out of their 10mm Glocks with no ill effects. Does that mean it is safe to do so, with no chance of ill effects? No, it doesn't, but no more so than firing 10mm out of a 10mm Glock, in my book anyway.
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It's not a super-high risk practice, but it does carry more risk of damage to the gun and more potential for danger than avoiding the caliber mismatch. The small potential for bullet material building up at the chamber mouth, for example, is non-existent in a .40S&W barrel firing .40S&W ammo. And the potential for extractor damage is also much smaller when the extractor is only doing the job it was designed to as oppose to when it's also having to hold the cartridge in place during the firing cycle.

The risk is not large, but it is larger than not mismatching the ammo and the chamber.
However, it is nice to know that if I am in a jam, in my book anyway, it is just as safe to use the .40 as what I would expect it to be firing the 10mm.
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In a jam, I would do it too. But I wouldn't deceive myself about the risk being totally non-existent. It's a small risk, but it's still higher than shooting the proper caliber for the chamber.
...if the passing of time would show a more favorable outlook on this practice today.
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I think that even the old thread probably mentioned that it's a reasonable practice in an emergency. That said, given the amount of time people spend discussing things like which oil is best to maintain a gun and how hard steel or aluminum cases are on a firearm, it's hard to imagine that a lot of folks with that kind of concern for keeping a gun in perfect working order would then turn around and do something that's known to have even a relatively small potential to harm their firearm unless they have to.
 
tipoc said:
You have no clue why he does it, so ask him. Then you'll have a clue.
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Don't have to ask him, I already have, many years ago, the first time I saw him do it. He says he does it because it works, so why not?

I still have no clue why he does it. Just because something will "work" doesn't make it a cause, explanation, or justification to do it.

rea·son
ˈrēzən/
noun
noun: reason; plural noun: reasons

1.
a cause, explanation, or justification for an action or event.
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Nice to know it can be done in an emergency

Outside of an emergency: How many people own a 10MM who do not own any other pistol? If you cannot find ammo that meets the manufacturers recommendation and fits correctly I really don't think its a great idea. Yeh I get the chance of failure is not high but we are talking a tremendous amount of pressure... your trying to control an explosion virtually in your hand.
 
Used by thousands in pistol comps? I don't understand how 40 S&W used routinely in a 10mm chambered barrel could yield consistent results--by definition the case is not headspacing properly in a reliably repeatable manner I would think, no? someone please explain. : )
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Your guy in the article doesn't know anything about competition shooting. Nobody shoots a G20 in USPSA Production division because it's scored minor, that is ruled by 9mm. Or if you do run a 40S&W, you download 180 gr to 700fps and wait 3 seconds for the bullet to get to the steel. Also 5,000 rounds a year in competition? 5,000 rounds a month is competition.

Step, it has nothing to do with head space. The 10mm is a "straight" wall case, as is the 40S&W. Actually there is .001" taper per side.... The round is held onto by the extractor, that's all. Try loading different OAL's for 10mm, from so long they won't chamber in a Glock barrel, and stick up over the breech tab of the barrel, to .100 short so that they fall well into the chamber. When a round is stripped off the mag, the extractor holds it until fired, simple. There is little difference between a short 10mm and a long 40S&W. In fact in competition it is very common to load 40S&W "long" Go to any USPSA match in the US and almost all Limited and L10 guys are running 40's long, and there will a few running 10mm guns loaded with 40S&Ws.
 
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Used by thousands in pistol comps? I don't understand how 40 S&W used routinely in a 10mm chambered barrel could yield consistent results--by definition the case is not headspacing properly in a reliably repeatable manner I would think, no? someone please explain. : )
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Your guy in the article doesn't know anything about competition shooting. Nobody shoots a G20 in USPSA Production division because it's scored minor, that is ruled by 9mm. Or if you do run a 40S&W, you download 180 gr to 700fps and wait 3 seconds for the bullet to get to the steel. Also 5,000 rounds a year in competition? 5,000 rounds a month is competition.

Step, it has nothing to do with head space. The 10mm is a "straight" wall case, as is the 40S&W. Actually there is .001" taper per side.... The round is held onto by the extractor, that's all. Try loading different OAL's for 10mm, from so long they won't chamber in a Glock barrel, and stick up over the breech tab of the barrel, to .100 short so that they fall well into the chamber. When a round is stripped off the mag, the extractor holds it until fired, simple. There is little difference between a short 10mm and a long 40S&W. In fact in competition it is very common to load 40S&W "long" Go to any USPSA match in the US and almost all Limited and L10 guys are running 40's long, and there will a few running 10mm guns loaded with 40S&Ws.
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Sometimes my Glock forgets where to look.....
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Thanks for "learning me." : )

As you know from other conversations I've had with you--I started running 9 x 25 dillon in my 20SF and was having issues with reliable feeding and firing--I know it may be purely coincidental--but I eventually found my brass was coming out of the die with the "shoulder" set too far back--and once I adjusted for that everything seems to have worked fine. Is there a certain amount of play involved between the extractor retaining the case rim and the chamber face?
 
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