9x18 brass mixed in with 380

[TennJed]

I noticed what appears to be a few 9x18 brass (headstamped 9mmM) mixed in with a bag of 380 range brass. Standing them up and checking with a naked eye, some appear slightly longer than the 380, but some do not.

What would happen if you loaded these as a 380 round? Would they chamber? Would they kaboom?

[lee n. field]

The case would probably go through the sizing die fine.

Likely the case would come out of the belling die flared way too much, and you'd see it when you went to seat the bullet. (Ever run a .357 case through a press set up for .38? Like that.)

If it made it through all that, The pistol probably would not go into battery, as the case is 1mm longer.

[chiefr]

Last 9x18 brass I picked up at the range was Berdan primed.

[chris in va]

Keep in mind, 9x18 uses a .365 bullet. 380 uses a .355 diameter.

[TennJed]

Originally Posted by chris in va

Keep in mind, 9x18 uses a .365 bullet. 380 uses a .355 diameter.

Probably should have been a little clearer in my original post. I don't want to do it, I was wondering what would happen if I accidentally did it

[hammie]

For the reasons above, I don't think you could accidentally reload a 9mm mak as a .380 and chamber it in a .380. (A 9 x 18 mm makarov won't even fit into my .380 acp shell holder.)

Of course the question then becomes: Could you intentionally use a 9mm Mak case to load 380's? It would depend on the tolerances of your breech face, extractor and chamber, but I think you could do it with some case modification and a lot of work.

[TechAlG]

I've accidentally loaded some 9mm Mak brass as 9 Luger. The sizing die seemed to size them down just fine. Only reason I noticed it was because it appeared the bullet was too far out of the case. After doing the thinking about whether it would blow my gun up, I tried it. It fed well, and shot normal.

Would I recommend doing it? No. Does it work in 9mm Luger? Sure.

[hammie]

@Mr Techaig: You're right. I can see how that could easily happen with the 9mm mak and the 9x19 parabellum. The problem is that using the 9mm mak creates an excessive headspace problem in the 9x19 chamber. In your case, the extractor and the taper of the case prevented it from going too far into the chamber on firing. However, I wouldn't want to rely on that phenomenon. The 9x19 operates a pretty high chamber pressures and a case separation could be nasty. And, of course, you're also correct: It shouldn't ever be done.

Anyway, interesting story.

[joneb]

I trim 9x19 to 18mm to load for a EG Makarov. I try to recover the brass, but some get away

[m&p45acp10+1]

If you somehow by accident tried to run a 9mm Mak case into a .380 sizing die it would not go in. If you were going fast enough you would likely crusn the case. If it went into a seating die it would badly mangle the case.

[Unclenick]

I don't know about the crushing. A couple of years ago I ran a .45 Auto case into one of my .44 Mag dies by mistake. The result was just a new bottleneck wildcat. The brass went in and out just fine, though. So that simply depends on the radius of the mouth of the sizing die. What should be noted, though, is that the case will get longer when you narrow it, so evaluation of the trim length should be done only after sizing. At that point my .45 Auto case would not have failed a case gauge check.

[smokin54]

I trimmed a quanity of 9mm luger by .043 (from memory) and then loaded it for my 9x18 mak using the proper dies , the mak ran like a champ as usual.