Out of stock on your case?

[Rick W.]

If you can't buy one case, then buy a 9mm the next size up. Maybe you have all these guns to save money on buying cases and just trim them down from one size to the next? If you start out with 9mm x 21 and after these cases can't be used anymore, then they can be trimmed down to 9mm Luger length. After these can't be used for this anymore, then they can be trimmed down again for 9mm Makarov. After they can't be used for this anymore, then they can be trimmed down once again for .380 Auto. The rest of the sizing can be done with your sizing dies. I like this because I can go to the range and if there's any 9mm Luger brass laying all over the place, then I can pick it up, take it home and use it to reload my 9mm Makarov(once fired works better than brand new 9mm Luger).

The problem with this is that it seems almost impossible to find ALL my cases after I get done shooting(that's headstamped as 9mm Luger) and it makes me wonder what the next reloader is thinking when he picks up my sized down 9mm Luger brass, takes it home to reload for his 9mm Luger and finds out that it's too short! Do they have stretching machines for brass cases?

[Eddie2002]

Never had any luck converting 9mm down to .380ACP, need to trim down the case mouth in the micro lathe then flip it around, trim down the base and recut the ejector groove. Tried a few and they never worked right in my Ruger .380acp. The 9mm and .380ACP take different size shell holders and are not interchangable unless the base gets trimmed and the ejector groove recut, too much work. It's just easier to buy the brass.
Don't have a 9mm Makarov so haven't tried that conversion.
Any short cases get stretched with a hammer whack. It stretches them nice and flat.

[Rick W.]

Well, I guess thats one way to stretch them! LOL We have 2 Makarovs. Both of them was 9mm, then I finally figured out what was wrong with one of them-it needed a new barrel. So, I changed the barrel and caliber to a .380 Auto and that was the only thing I had to change. The clip feeds the .380 rounds just as good as it did when it was a 9mm Makarov and the ejector ejects them the same too. The only thing I had to change is that the 9mm case needs to be trimmed down from the Makarov dimension of .703 to the .380 Auto dimension of .680. The case also needs to be resized in diameter because the Makarov takes the .365 diameter boolit and the .380 takes the .358(.356)diameter boolit. There's only .005 differance at the thickness of the base of the case between the Makarov compared to the .380. The Luger has the same size base as the Makarov. The diameter of the base is also the same in all 3 cases. But, the body of the case itself does need to be resized with a sizing die to meet the slight differances with the different calibers. The reason for the different size of shell holder is because the diameter of the extractor groove is slightly smaller, but the head diameter is still the same with them all.

[Eddie2002]

Sounds like you have a good plan and setup. Didn't think about doing a rebarrel from 9mm to .380acp, that would take care of the size differences between the two cases. Couldn't get 9mm to feed in my Ruger, cases are too big.

[Rick W.]

Your pistol sounds like it's a lot pickier than mine. The only thing I don't like about changing out this barrel from 9mm Makarov to .380 is that I have to be careful that I don't get mixed up between the 2 pistols we have and load the wrong bullet into the wrong pistol. I think that is how this barrel got bad was because someone before me loaded 9mm Luger bullets(.355 dia) into the 9mm Makarov(.365 dia)pistol and the smaller bullet chattered as it went down the barrel. There was chips in the lands, which affected accuracy. I wish I would have seen these chips before I bought the gun! The .380 is also a .355 dia barrel, but I don't think it would be a good thing to load a Makarov bullet(.365 dia)into it! The advantage of having the .380 barrel instead of the Makarov barrel is that I have a lot more choice on what kind of bullets to load into the pistol.

[country gent]

You need to watch internal case taper when doing this shortenint or you can end up with rounds that ae to thick in the neck are to chamber doe to loaded rounds neck dia. CAses wall thickness gets heavier as you go back to the case head meaning as you shorten the case neck wall gets heavier also. I doubt a 9mm markarov round with .365 dia bullet will chamber in the 380 due to dia before case lebgth becomes an issue.

[Rick W.]

Country gent-I just got done checking and you are right. I took my slide off and the 9mm Makarov round won't fit into the chamber of the .380. Now, that's a little bit of a relief to me. But the case from the 9mm Makarov can still be cut down and resized with the sizing die to fit the .380 barrel. And the 9mm Luger case can be cut down and resized to fit either the 9mm Makarov or the .380.

[country gent]

Yes they ca be sized down to fit and with some brass due to internal taper of the case when a jacket bullet is seated it opens outside bak up to a snug / tight fit. Lead bullets may be swaged down undersized when seated. Section a case carefully and measure wall thickness at mouth, mid point and just ahead of case head. Cut a case in half or just off of center then polish the thick half with sand paper to remove burrs , ussually the wall taper can be seen with the eye. Your right it can be done and sometimes its easy reform but some cases or conversions may require a ream step to remove taper from case walls also.

[Eddie2002]

Finally got around to chcking case dimensions for 9mm and .380acp. The 9mm has a base of .394 according to my Speer #9 book and the .380acp has a base of .374. Twenty thousands difference is why a 9mm won't fit a in a .380acp magazine or action. I miked some loose brass and found that most 9mm measured around .388 while the .380acp measured at .370.
Rebarreling a 9mm to a .380 acp is kind of a wildcat cartridge but sounds like a good way to get a shooter back out there, great idea.
Just as a a side light I tried cutting down .223 brass to .380 length. The base was the correct size but the internal taper in the case made the wall way too thick. Couldn't seat a bullet properly without reaming the inside of the case. It would given some brass rat a real puzzle if it worked and I left some at the range. ;)