Shooting .380 in a 9mm

Discussion in 'The Ammo & Reloading Forum' started by CampingJosh, Feb 15, 2011.

  1. CampingJosh

    CampingJosh Well-Known Member

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    So I got my first 9mm recently, and yesterday I got the urge to see if my .380 ammo would cycle well in it. I was a little surprised, but it actually hand-cycled very smoothly, and it didn't have any issues loading into or feeding from the magazine.

    I think I already know the answer to this, but I am not a reloader, so I wanted to confirm with some who are more knowledgeable than I. Would there be anything unsafe about firing .380 ammo in my 9mm Luger pistol? In an emergency, could I use it as a substitute?

    I really kinda want to see if it will function reliably. :cool:
  2. RandyP

    RandyP Member

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    I will presume that you are either VERY new to guns or maybe just having a bit of fun on a Tuesday evening?

    There is NO upside to firing the wrong caliber ammunition in firearms.

    .380 has a different case shape than its cousin the 9mm, same goes for the gun's chamber.

    Life is a series of choices and everyone gets to make their own and live with the results. But like Mrs. Gump taught her son...."Stupid is as stupid does."
  3. CampingJosh

    CampingJosh Well-Known Member

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    It's the latter. Seeing if it would fit, if the .380 was truly a shorter 9mm case or if they were just nominally the same dimension.

    I'm not asking if it would an improvement; I know that 115 grains at 1300 fps is better than 95 grains at 950 fps. I'm asking if it would be likely to fire. Would my 9mm pistol hold the .380 in the appropriate place that the firing pin would reach it? Would the .380 somehow create too much pressure by being in the wrong chamber? These are the things I'm wondering.
  4. 312shooter

    312shooter Active Member

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    You guys got my curiosity with this one, put your gun in a vice with a 20 foot string tied to the trigger, hide around a corner with the string in hand and pull off a round. At least you might not get hurt and it only destroys your gun.....Wait.....umm..nevermind
  5. Texxut

    Texxut Member

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    Will it fire, probably, if the extractor holds it against the bolt face.
    Is it a good idea, no.
    Will it cycle the pistol, not likely.
    Will it damage the extractor, possibly.
  6. woolleyworm

    woolleyworm Active Member

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    Big safety issue here is that 9mm and 380 both headspace off the mouth, not the rim like a 38/357. This changes everything as far as safety goes. I wouldn't fire 380 in a 9mm even if it was a SHTF situation, better off with a bat.
  7. johnlives4christ

    johnlives4christ Former Guest

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    i dont expect it would cycle an automatic, but i'd be surprised if you lost a finger hand or face. not the best idea, but it would work
  8. Jay

    Jay New Member

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    Bad idea to even try it....
  9. upsguy

    upsguy New Member

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    Easiest way to explain this answer is to read the first Sticky thread at the top of this page, "Explaining Headspace"
    If someone dosn't understand it, you shouldn't be handling guns or ammo.
  10. Warith

    Warith Member

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    I have fired a 9mil in a 380 and a 380 in a 9mil niether one hurt the gun nor me. The 380 in the 9 fired just fine missed the target completely and didnt cycle the gun the 9 the 380 fired and cycled the gun just fine but didnt want to go to battery.

    One cavat here I didnt do this on purpose had both guns and ammo at the range and screwed up they were both hi points which are exactly the same pistal just the barrel is defferent they even use the same magazine which is what screwed me up. I dont take both guns to the range at the same time anymore.
  11. CampingJosh

    CampingJosh Well-Known Member

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    Here's the answer I was looking for! :) Thanks, Wolley.

    I had no intention of firing it. The 9mm cost just over half the .380, so there isn't a reason to fire the .380s in the gun that can fire cheaper ammo. I was just wondering if it was like the .38/.357 or not.
  12. carver

    carver Moderator

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    Aside from the head spacing problems you would encounter, there are presures to consider. The .380 operates at around 17,000psi - 20,000psi. The 9mm operates at presures from around 33,000psi - 34,000psi.
  13. RandyP

    RandyP Member

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    Hi Josh,

    No offense intended by my smart-a$$ reply but you posted:

    "Would there be anything unsafe about firing .380 ammo in my 9mm Luger pistol? In an emergency, could I use it as a substitute?

    I really kinda want to see if it will function reliably"

    That reads to me like somebody who had plans on pulling the trigger. If you truly want to plan for the end of the world and zombies? Go buy yourself a spam can of Tula/Wolf/Herter's in 9mm and leave it in the closet.
  14. CampingJosh

    CampingJosh Well-Known Member

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    No offense taken. Don't worry about it.

    I don't expect the end of the world or zombies.

    And I did "kinda" want to try it. I kinda want to try a lot of things, but I don't want to get into a dangerous situation because of curiosity. (I got most of that out of my system with a baseball pitching machine before I was a teen.)

    Because I didn't know what would happen, I asked. It's certainly much safer than going in blind, even if I get some ridicule for asking. I've never been too proud to admit my ignorance on a topic, even to mean-spirited people, so certainly not to the friends I've made on TFF.
  15. RandyP

    RandyP Member

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    In the 'olden days' what I said was there for the hearing to only those within earshot of my random ramblings.

    The 'curse' of the internet is that whatever you write is out there for all eternity ready to be seen and even worse believed by whoever reads it. That creates the potential for the "hold my beer and watch this" set to makes all forms of bad choices based on what they saw on the 'net and tried in their home.

    Heck, I won't even post reloading data that I am POSITIVE is good just because there is always the possibility of a typo.
  16. CampingJosh

    CampingJosh Well-Known Member

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    Sorry to dredge up an old thread, but it was linked in a current discussion, and so my attention returns here. And please, don't take this post as a recommendation. I'm not advocating anything below.

    As I've learned more over these last few years, I'm convinced that there is very little chance of a dangerous situation from firing .380 in a 9mm gun. It may not work (because the firing pin may or may not actually reach the primer), and it certainly won't cycle the action, but it's not going to generate too much pressure.

    The only possible issues I can forsee would be (1) a failure of the case to properly seal the chamber, which could lead to some gas escaping around the bolt, and (2) possible damage to the extractor. Not ideal, but I doubt it would be dangerous.
  17. Tony C C

    Tony C C New Member

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    I don't know about firing one in the other (which I would not do on purpose) but I do know for sure that 9mm brass can be reloaded as .380 because just lately I purchased some .380 reloads and to my surprise when loading up some magazines I noticed that about half of the rounds were head-stamped as 9mm. Sure enough after checking the brass size/length I found that the brass was exactly the same diameter but 9mm rounds are just about 3/32 longer than a .380 brass so you take the 9mm brass and trim it to the correct length and you have a .380 brass.
  18. gdmoody

    gdmoody Moderator Supporting Member

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    Welcome to The Firearms Forum Tony. Even though you can trim 9mm down to the size of a .380 I have found that in my Dillon press the .380 shell holder is just a hair smaller that the 9mm. I have picked up a 9mm case by mistake and found that it would not fit in the .380 shell holder.
  19. Alpo

    Alpo Well-Known Member

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    Some years back I read about loading for a Mak, before 9x18 was available here. The guy was cutting down 9mm luger cases. Reason is that the Luger case is tapered. While the mouth is 355 ID to hold the 355 bullet (380 OD), the back end is 391OD.
    http://stevespages.com/jpg/cd9parabellum.jpg

    Since the Mak is almost straight 392 to 390, you can make Mak brass out of luger.

    http://stevespages.com/jpg/cd9makerov.jpg

    380 is straight - 374 at the back, 373 at the front.
    http://stevespages.com/jpg/cd380acp.jpg

    So - NO, the brass is NOT "exactly the same diameter". 9 mil brass is 20/1000 bigger in diameter than 380.

    You can shoot it, if your extractor will hold it against the bolt-face. It will swell, although probably not enough to rupture. It should not be dangerous. In a push-come-to-shove situation, I'd do it. But not as an everyday thing.
  20. racerham

    racerham Member

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    I've made the mistake of running .380 through a 9mm. It was discovered when the gun didn't cycle properly. One should ALWAYS check anything suspicious when loading the magazine. I thought it looked short...

    It fired, the bullet left the barrel and hit the target. The gun didn't cycle enough to eject, leaving the brass in the chamber. Inspecting the brass afterwards, the brass is bulged unevenly over the top third to half. It's not symmetrical around the circumference but only malformed around about 270 degrees. There was no damage to gun.

    So, running .380 through a 9mm could be thought of as a dangerous way to turn your 9mm semi-auto into a hand-racked, inaccurate single shot.
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