10mm vs .40 rounds

[Alan0354]

380 fit in 9mm chamber of Glock 26

OK, here are more telling pictures. I decided to take a 380 round and put it in the barrel of my Glock 26. Here are the pictures:

1) This is a 9mm round fit into the Glock chamber. Notice the back of the round is flushed with the top part of the barrel as indicated. This is the breech surface line.

2) This is a 380 fit into the Glock chamber. Notice the round sunk into the chamber, there's a min of 1/8" gap from the top of the barrel which represents the breech surface. There is no way the firing pin can reach the primmer without the help of the extractor.

If you have a 10mm, take the barrel out and put a .40S&W round in. There will be no debate if it is like what I see here.


BTW, I am having a hell of the time putting the Gold Cup back!!! I forgot how to take it apart, I had to watch youtube to figure it out. Now the plastic cushion on the main spring is coming apart after 30 something years. Now I have to go buy it. I still have not succeed in putting it back together!!!

 

[Nanuk]

I guess Colt had it wrong with the 38 Super.

Alan, if the case always made contact with the barrel as you suggest, then a slightly long case would inhibit function.

As I already said, if you do not want to do it, don't. I do it and will continue to do so. If after 25,000 rounds my extractor breaks I will install another.

 

[Nanuk]

I can say with confidence this hold true for 45 and 9mm. and I can say for sure this is going to happen if you try to shoot a 380 in a 9mm gun. It's up to you guys to do the testing on .40.

.380 and 9mm is not the same as 10mm/40. .380 case is .020 smaller in diameter than a 9mm case. the 40/10 are identical.

It's easy, take the 10mm barrel out, fit a .40 round, if the rim drop pass the mouth of the chamber, you know the extractor is taking all the stress from the firing pin hitting.

And exactly how much is that?

 

[Alan0354]

I guess Colt had it wrong with the 38 Super.

Alan, if the case always made contact with the barrel as you suggest, then a slightly long case would inhibit function.

As I already said, if you do not want to do it, don't. I do it and will continue to do so. If after 25,000 rounds my extractor breaks I will install another.

Yes, I can say for sure 9mm and 45 both stopped by the inside of the barrel, not by the rim of the casing.

Just take a barrel out and try. Look at inside of a barrel. I can say for sure you have a step down in diameter for 45 and 9mm. I don't have a 10mm gun, so I cannot say for .40. Any of you guys has a 10mm, it's so easy to try it out like what I did.

I guess if you are ok riding on the extractor, it's your gun!!

 

[Alan0354]

.380 and 9mm is not the same as 10mm/40. .380 case is .020 smaller in diameter than a 9mm case. the 40/10 are identical.



And exactly how much is that?

Should be the difference in length between the 10mm and the .40 casing.

Just follow post#121 since you have a 10mm. Take pictures and show us. It's easy.

 

[Nanuk]

Should be the difference in length between the 10mm and the .40 casing.

Just follow post#121 since you have a 10mm. Take pictures and show us. It's easy.

No. You said the force of the firing pin on the primer. That would be based upon the surface area of the firing pin, you would need to figure the radius since it is round. Then you would need to figure out how much force it takes for that surface area to detonate said primer. Either way it is insignificant.

Show me a 10mm extractor broken by this VS just broken from a defect or use. The extractor by design holds a loaded case to the breech face, the round is snug in the chamber not flopping around in space, besides it is not that heavy.

You are not going to convince me with conjecture. I am going to keep shooting 40's and 10's in my 10mm's. Just like I am gonna keep shooting 38's in my 357's. If I break an extractor I will post pictures about it. Until then, you can consider it an experiment is process. If it means that my $40 extractor lasts 100,000 rounds instead of 200,000 rounds I am good with that.

 

[Alan0354]

Look, you can do what you want, this is FYI for other people that unless you can BE CERTAIN that the .40 will not sink in like in post #121, then the only way of firing the round is using the extractor to hold the round against the breech.

As for firing pin, you can find a way to push the firing pin out and see how far it can come out of the breech surface. Say if it can come out say 1/8", then if the shall casing can sink into the chamber more than 1/8", the firing pin will not even touch the primmer when fired. There's no way the gun can ignite the round. Like the picture of 380 in 9mm chamber, the firing pin cannot even touch the primmer if not for the extractor holding the round against the breech.

This is very very simple!!! Just take a 10mm barrel out, fit a ,40 round in the chamber and look at how far it sunk in!!!

We are going nowhere with this. Just try it and take a picture!!!

 

[Alan0354]

BTW, firing a 38 in 357 is a completely different thing. The rim of the casing is the one that stop the round from going further into the chamber. Just look at the 38 and 357 casing. It works just fine.

If you have any question, read the post 118 and 121. I don't know how to be clearer than what I have said already.

 

[Nanuk]

If you have any question, read the post 118 and 121. I don't know how to be clearer than what I have said already.

Alan,

I fully understand what I am doing. I fully understand what you are saying. I am disagreeing with you that it is a real issue, that is all. I was an agency armorer with the US Border Patrol for H&K pistols & submachine guns as well as Colt M-4 and Remington 870's. I have been doing this for a few years.

 

[Nanuk]

Look, you can do what you want, this is FYI for other people that unless you can BE CERTAIN that the .40 will not sink in like in post #121, then the only way of firing the round is using the extractor to hold the round against the breech.

What I am doing is perfectly safe. Worse case scenario, the case misses the extractor. The gun does not go bang. I have fired hundreds of 40's this way with zero malfunctions. any case support issues would be at the rear, not the front. It is not a tapered case like the 9mm or a bottleneck.

As for firing pin, you can find a way to push the firing pin out and see how far it can come out of the breech surface. Say if it can come out say 1/8", then if the shall casing can sink into the chamber more than 1/8", the firing pin will not even touch the primmer when fired.

It is not an accurate measurement to push the firing pin to see how far it pokes. You would have to measure the force that the hammer strikes it with VS the spring pressure on the firing pin spring.

There's no way the gun can ignite the round. Like the picture of 380 in 9mm chamber, the firing pin cannot even touch the primmer if not for the extractor holding the round against the breech.

You are correct. What is the problem?

 

[Alan0354]

No, you can do what you want, it's your gun and it's your life. PLEASE, DO NOT TELL OTHERS IT"S OK. Don't ruin other's gun just to be right.

 

[Alan0354]

What I am doing is perfectly safe. Worse case scenario, the case misses the extractor. The gun does not go bang. I have fired hundreds of 40's this way with zero malfunctions. any case support issues would be at the rear, not the front. It is not a tapered case like the 9mm or a bottleneck.



It is not an accurate measurement to push the firing pin to see how far it pokes. You would have to measure the force that the hammer strikes it with VS the spring pressure on the firing pin spring.

It is accurate measurement if the firing pin cannot reach the primmer


You are correct. What is the problem?

OK, you follow what I am saying. If the casing goes in beyond the firing pin can reach, why the round fired? Just answer this first.

 

[Alan0354]

OK, let me try another way. Look at this picture: The firing pin can only reach so far. It's easy to find out, just push the firing pin out and it will STOP when it reach the max extension. Just that simple. Measure how much it comes out of the breech surface.

Look at the diagram. If the casing sunk in to the point the firing pin cannot reach. You agree there is no way to ignite the round?

If you can still fire the gun, my question is WHO IS HOLDING THE ROUND to keep it from bottoming out.....so the firing pin can hit the primmer and ignite the round?

This is really simple.




EDIT, I just checked, 10mm casing is 25mm long. The .40 casing is 22mm long. That's a whopping 3mm difference. if the .40 casing actually sunk into the chamber, I firing pin at best can barely touch the primmer, not enough to dent the primmer. So why the round can still fires?

 

[Nanuk]

No, you can do what you want, it's your gun and it's your life. PLEASE, DO NOT TELL OTHERS IT"S OK. Don't ruin other's gun just to be right.

It is not unsafe. You, nor has anyone offered evidence that it is either dangerous or destructive. You are offering only conjecture.

If the casing goes in beyond the firing pin can reach, why the round fired? Just answer this first.

The only way for that to happen would be to miss feed.

If you can still fire the gun, my question is WHO IS HOLDING THE ROUND to keep it from bottoming out.....so the firing pin can hit the primmer and ignite the round?

It is not who, it is what. The extractor is holding it. It works, what is so difficult for you to understand? The case is held tight to the breech face by the properly adjusted extractor, it is not rocket science.

My Mechtec 10mm works that way, Glocks work that way and a 10mm 1911 works that way.

 

[Nanuk]

Alan, buy reading some of your other threads you readily admit that regarding firearms you are a novice. So my question is why are you beating this to death?

 

[Alan0354]

It is not unsafe. You, nor has anyone offered evidence that it is either dangerous or destructive. You are offering only conjecture.



The only way for that to happen would be to miss feed.



It is not who, it is what. The extractor is holding it. It works, what is so difficult for you to understand? The case is held tight to the breech face by the properly adjusted extractor, it is not rocket science.

My Mechtec 10mm works that way, Glocks work that way and a 10mm 1911 works that way.

AH, so you finally admit it is ONLY the extractor that is holding the round when the firing pin strike.

That we are in agreement. People can read this carefully and make their own decision whether it's safe. Honestly I never even give this any thoughts until Aguila Blanca described it. It made a whole world of sense. People already complain about Glock with MIM extractor that don't slam the slide onto a loaded chamber. This definitely bring the stress on the extractor to a higher level.

Also, I doubt any gun chamber with the correct rounds work this way where the extractor is holding the round to be strike. The round is held in the chamber.

BTW, it's not the years of experience that make the argument. I have been an engineer for 3 decades, I published papers in the prestige America Institute of Physics and I own patents solely under my name. But that does not make me more right, it's the science and facts. I think I explained in detail already in posts 118 and 121. people can make up their mind whether it's is safe, it's not because of you said so or I said so. The facts is here. They can decide on their own.

Let's just end this, it's going nowhere. We presented our points, it's very clear and people can make up their mind.

Peace.

 

[Aguila Blanca]

It's easy, take the 10mm barrel out, fit a .40 round, if the rim drop pass the mouth of the chamber, you know the extractor is taking all the stress from the firing pin hitting.

And exactly how much is that?

See post #114. How much is difficult to impossible to quantify with any exactitude due to the number of variables involved:

Strength of hammer spring
Weight (mass) of hammer
Strength of firing pin return spring
Weight (mass) of firing pin
Hardness of primer cup
Distance firing pin has to travel before contacting primer

Although we can't quantify the force with which the firing pin impacts the primer, and therefore we can't quantify the resultant axial stress on the extractor, we do know that the force and stress are not zero -- which is what you have stated is the case.

Every time a round feeds it slips up under the extractor from the magazine. There is no stress on the extractor.

My Mechtec 10mm works that way, Glocks work that way and a 10mm 1911 works that way.

I don't know how a Mechtech carbine works and I don't know how Glocks work, but I do know how 1911s work. And I know that 10mm 1911s headspace on the case mouth, not the case rim on the extractor.

 

[Alan0354]

...................
I don't know how a Mechtech carbine works and I don't know how Glocks work, but I do know how 1911s work. And I know that 10mm 1911s headspace on the case mouth, not the case rim on the extractor.

I have no idea about the 10mm Glock. I do know for fact the 9mm Glock 26 I have, the case is rest on the chamber, not the extractor. Here are the two pictures, the first one is the old picture in post 121 where the bottom of the case is FLUSH with the top of the barrel which touches the breech face. So that's the surface of the breech:

Now, this is a close up picture where you can see day light between the back of the shell and the breech face see (2) in the picture. Also you can see daylight from the extractor claw to the rim of the case, see (1) in the picture. You can see there is quite a big gap between the extractor claw to the rim of the case. With the gap between the breech face and the case, this means when the case rest in the chamber, the extractor cannot be touching or holding the case and holding on the case to let the firing pin hits.

I think this is a strong scientific proof at least for 9mm Glock, the extractor is NOT holding the case when firing pin hits. It's not even close.

Someone should take picture like this for 10mm. Just take out the slide, push a case onto the breech, place with a white background and take the picture. Then we can have the conclusion whether the extractor is holding the case in normal firing with the correct round.

 

[JohnKSa]

It's not especially dangerous, it does stress the extractor more than normal.

There is one low-probability outcome that is potentially dangerous. Because autopistol chambers have a sharp step at the front of the chamber, it is possible that bullet material can shave off and build up on this sharp step when shooting a round that is shorter than spec for the caliber. This normally can't happen because the case mouth sits on that sharp step, but when the extractor is being used to hold a shorter than normal case in place, that step is exposed.

If there's a significant buildup, it can cause one of two problems. It can make it difficult or impossible to chamber the proper caliber of ammunition until it is cleaned out, but that's really not dangerous.

The second possible negative outcome is for the buildup to tighten up the front of the chamber when the standard caliber for the chamber is used again. That can cause issues with the case mouth releasing the bullet properly which could potentially cause an overpressure event. It doesn't seem to be a likely outcome as we read about people doing it and getting away with it on a regular basis, but it is a possibility.

If I were going to shoot the wrong caliber ammunition in an autopistol chamber (revolver chambers are usually quite different and don't have the same problems) I would be really careful to clean the chamber before going back to the proper caliber. By the way, it's pretty common for manufacturers to warn against the use of anything but the marked caliber in autopistols while the same is not true of revolvers.

At one point I found a S&W manual that specifically said it was OK to use .40S&W in their 10mm guns--but only in their revolvers. Which makes perfect sense given the differences between revolvers and autopistol chambers. Here's the quote from the manual.

Additional ammunition calibers can be fired from the following list of select calibers.
Caliber on Barrel----- Can also Fire
.45 Colt------------------.45 Schofield, .45 S&W .45 S&W .45 Schofield
.44 Magnum-----------.44 Special
.357 Magnum---------.38 Special, .38 Special +P
.22LR-------------------.22L, .22 Short, .22CB, .22BB (in revolvers only)
10mm------------------.40 S&W (in revolvers only)​

 

[Alan0354]

When I said dangerous, it's more dangerous to the gun. Although if you use a shorter round, can you guaranty 100% the extractor is going to catch the shorter round? If it miss, the round will go deep into the chamber, you cannot clear the chamber by racking the slide as the extractor won't be able to pull the round out. You have to drop the mag, use a stick to push from the front of the gun to get the round out.

In the middle of shooting, this is a long jam and can cause your life.

Regarding to shooting .40 in 10mm revolvers, here is an article:
https://revolverguy.com/psa-40-sw-in-the-10mm-gp100/
Sounds like you need a moon clip for that and still not very good.

22, 357 shooting 38 is a totally different situation. They all have wide rim, the casing is held in position by the rim, there is no issue with rounds going deep into the chamber.

Ha, I wonder whether Desert Eagle can fire 38 rounds!!!

too bad I don't think I would get a 10mm gun. I am looking for Sig2022 .40, I am trying to find a DA/SA gun, the only other I know of is HK P2000SK 40. If not, I am leaning towards 45ACP even if I get another Glock. It's not very attractive to get a 10mm. For home defense, I rather want a slower velocity rounds like 45. It's not as dangerous in going through walls. The 10mm velocity is too high. So it's going to be .40 or 45. Or else, I would have all the answers as soon as I get the 10mm gun.