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Just curious - I know that shooting .38 special out of a .357 magnum cylinder is okay - what about shooting .380auto out of a 9mm cylinder? Has anybody tried this? Is it potentially bad for the cylinder?

I have a Blackhawk conversion model that shoots both .45Colt and .45acp. I noticed that in the .45acp cylinder, there is a sort of "step" where the chamber diameter abruptly shrinks. I supposed that because the ACP cartridge does not have a rim, the "step" is where the cartridge has a stopping point to make sure the rear of the cartridge is in a proper position for the firing pin to work correctly. I don't (yet) own a 9mm blaclhawk, but I suspect the 9mm cylinders are the same way also due to their lack of a rim.

One other thing, is the SP101 also "convertible?" I am aware they make 9mm SP101's, but I figured that swapping the cylinder in a double-action revolver is something a qualified gunsmith ought to do - it's not the simple operation that it is on a single action. Anyway - as far as shooting .380 in a 9mm SP101, I suppose that's probably doable since a moon clip acts as the rim and the OAL of the cartridge isn't a factor in that case.
 

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Just curious - I know that shooting .38 special out of a .357 magnum cylinder is okay - what about shooting .380auto out of a 9mm cylinder? Has anybody tried this? Is it potentially bad for the cylinder?

One other thing, is the SP101 also "convertible?" I am aware they make 9mm SP101's, but I figured that swapping the cylinder in a double-action revolver is something a qualified gunsmith ought to do - it's not the simple operation that it is on a single action. Anyway - as far as shooting .380 in a 9mm SP101, I suppose that's probably doable since a moon clip acts as the rim and the OAL of the cartridge isn't a factor in that case.
You cannot shoot 380 from a 9mm revolver. The case on the 380 is tapered differently from the 9mm and 380 cases will rupture, causing a dangerous condition. Dont do it.

They MADE SP101 9mm revolvers early on when the SP101 was introduced. They are now highly collectable, not easily found, and when they are found, command premium prices(currently very close to $1,000)

Once again, shooting 380 from a 9mm revolver is a bad idea because of the different taper of the 380 cartridge, as opposed to the 9mm.
 

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I don't know about the double action but your assumption on the single action 9mm cylinder and the "step" is correct.

You can NOT shoot .380 (9mm short) because the cartridge will drop too far into the cylinder for the firing pin to make contact.
 

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Discussion Starter #4
Thanks weblance and Quiet 1. I didn't realize that .380 had slightly different taper than the 9mm. I figured they had a similar relationship as 10mm does to .40s&w.

Would be nice if revolver makers made more 9mm caliber revolvers, but with 9mm autos so inexpensive, reliable and widespread, that's not a sound financial decision.
 

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Yes. What you have to think of is how they get a rimless round to fire in a single-action revolver.

Once you do, you realize that since there's no rim to hold it in place so the firing pin can hit the primer--it has to fit perfectly.

The .380 would be too short and if it did happen to go off somehow (I suppose it could if you elevated the barrel) the difference in shape would probably cause the casing to fail.

Bad business.

If memory serves, some of the double-action 9mms had wire loops to hold rimless in place.
 

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I don't know anything about a "different taper" on a .380 case. :confused: Other names for .380 ACP include .380 Auto, 9mm Browning, 9mm Corto, 9mm Kurz, 9mm Short, and 9×17mm.

I believe it's only the length of the case that's different although there may be a few thousandths difference in the diameter??? As far as I know the only reason you can't shoot them from the 9mm cylinder is they drop too far into the cylinder because of where the "neck" is cut. Thus, the firing pin doesn't make contact.

As far as the cases rupturing, I doubt it. At the worst they may expand enough to make it difficult to eject them. But, I doubt that too.
 

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Yes. What you have to think of is how they get a rimless round to fire in a single-action revolver.
Ruger SA's do it by way of cutting a "neck" into the cylinders which "catch" the cartridge by the case's rim. There is no moon clip required.

What the OP was inquiring about is, could he shoot a 9mm short (.380 acp) from the 9mm (also a "rimless" cartridge) cylinder. Actually, he could if the "necks" in the cylinder walls were cut to accommodate the length of the .380 rather than the 9mm.
 

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Yeah, I got it in the first place.

And moon clips are used in some rimless double-action revolvers. There was also one with wire loops.

Your solution would give him a .380, which is maybe not a bad idea but the factory would have to cut it that way in the first place......hard to add steel after the fact.

I don't suppose there would be a big demand for the .380 cylinders though.

:)
 

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I don't know anything about a "different taper" on a .380 case. :confused: Other names for .380 ACP include .380 Auto, 9mm Browning, 9mm Corto, 9mm Kurz, 9mm Short, and 9×17mm.

I believe it's only the length of the case that's different although there may be a few thousandths difference in the diameter??? As far as I know the only reason you can't shoot them from the 9mm cylinder is they drop too far into the cylinder because of where the "neck" is cut. Thus, the firing pin doesn't make contact.

As far as the cases rupturing, I doubt it. At the worst they may expand enough to make it difficult to eject them. But, I doubt that too.
I guess it actually isnt a taper. The case is a different diameter, the rim is a different diameter, and obviously, the case is a different length. It has long been known NOT to fire 380acp in a 9mm revolver.
 

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. . . . I don't suppose there would be a big demand for the .380 cylinders though.
That my friend, is probably the understatement of the year. :D :D :D
 

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I'm resurrecting an old thread, but have a question about shooting 380 out of the 9mm cylinder.

I'm looking at buying my first Ruger Blackhawk. I found one online but the seller stated..."Comes with 1 - .357/.38 cylinder and 1 - 9mm cylinder. I also tried shooting .380 out of the 9mm cylinder and it shoots fine!"

I've searched a few threads and it was cautioned against shooting 380s out of the 9mm. Is there something I should inspect/be concerned about?

Thanks.
 

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flyingsquirl001 , If you look inside the chambers of a 9mm cylinder, you will see a "step" where the case diameter transitions down to bullet diameter. This is where the case mouth contacts the transition and stops the case from seating too deep in the chamber. This concept is called "headspacing on the case mouth", versus "headspacing on a rim" for a 38 or 357 cartridge. If you look in any reloading manual or cartridge reference source, you will see a 9mm case is notably longer (.754") than a 380 Auto case (.680"). Also, a 380 Auto case is slightly smaller in diameter than a 9mm case (.373" for a 380 Auto versus .380" for a 9mm. So what happens is …. a 380 Auto cartridge will seat too deep in a 9mm chamber …. usually so deep that the firing pin will not reach the primer. But even if the 380 cartridge does fire, the case is likely to rupture.

The reason why 38s and 357s will interchange and shoot reliably is …. they headspace on the rim so even though a 357 Mag chamber is about .1" deeper than a 38 Special chamber, a 38 Special cartridge will headspace properly in a 357 Mag chamber.

So …. it is never a good idea to shoot a cartridge in any gun that was not designed for it. That means shooting 9mm Luger in the 9mm cylinder and 38 Special or 357 Mag in the 357 cylinder.
 

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I'm resurrecting an old thread, but have a question about shooting 380 out of the 9mm cylinder.

I'm looking at buying my first Ruger Blackhawk. I found one online but the seller stated..."Comes with 1 - .357/.38 cylinder and 1 - 9mm cylinder. I also tried shooting .380 out of the 9mm cylinder and it shoots fine!"

I've searched a few threads and it was cautioned against shooting 380s out of the 9mm. Is there something I should inspect/be concerned about?

Thanks.
Yeah... DONT DO IT. The Blackhawks have a headspace ridge in the 9mm chambers. Thats where the autoloader cartridges register against to achieve the correct depth, so that the firing pin can impact the primer correctly. The 380 case is shorter than 9mm, so the only way it can be at the correct depth is purely by chance. It is dangerous to shoot 380 from a Blackhawk 9mm cylinder. You risk split cases, and pierced primers.

DO NOT SHOOT 380 FROM A 9MM BLACKHAWK CYLINDER
 

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flyingsquirl001 , If you look inside the chambers of a 9mm cylinder, you will see a "step" where the case diameter transitions down to bullet diameter. This is where the case mouth contacts the transition and stops the case from seating too deep in the chamber. This concept is called "headspacing on the case mouth", versus "headspacing on a rim" for a 38 or 357 cartridge. If you look in any reloading manual or cartridge reference source, you will see a 9mm case is notably longer (.754") than a 380 Auto case (.680"). Also, a 380 Auto case is slightly smaller in diameter than a 9mm case (.373" for a 380 Auto versus .380" for a 9mm. So what happens is …. a 380 Auto cartridge will seat too deep in a 9mm chamber …. usually so deep that the firing pin will not reach the primer. But even if the 380 cartridge does fire, the case is likely to rupture.

The reason why 38s and 357s will interchange and shoot reliably is …. they headspace on the rim so even though a 357 Mag chamber is about .1" deeper than a 38 Special chamber, a 38 Special cartridge will headspace properly in a 357 Mag chamber.

So …. it is never a good idea to shoot a cartridge in any gun that was not designed for it. That means shooting 9mm Luger in the 9mm cylinder and 38 Special or 357 Mag in the 357 cylinder.
Excellent!
 

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If he was somehow shooting 380 in a 9mm, I would think he likely damaged the head space ridge in the cylinder.

Maybe it didnt,, But I cant see how it would not damage it.
 

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I've seen probably a half dozen people accidentally load and fire .380 ammo in various 9mm Luger automatics. They will usually fire because the extractor helps hold the case in about the right location for the firing pin to still reach the primer, which would not happen in a revolver.

All of the .380 cases I've seen from a 9mm were somewhat bulged, but none of them ruptured. The .380 is a relatively low pressure cartridge and although the 9mm chamber is "looser", it was not enough to cause ruptures. Because of the low pressure, the automatics did not cycle and the slide had to be manually racked to eject the fired case.
 

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Basically like others have said don't do it. Below a visual. A 38 Special, 9mm Luger and 380 ACP



And here they are in the 9mm cylinder of a Ruger/Williams 357/9mm convertible blackhawk.

 
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