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?

[roverboy]

I'd definately separate them and not load the 9x18 brass as .380. I don't know what would happen if you accidently loaded some 9x18 brass as .380. I do know that 9x18 rounds have .364-.365 bullets. Thats roughly .010" bigger.

Edited March 16, 2013 by roverboy

[ttocswob]

Unlikely to chamber - the base diameter for 9x19 9x18 is .392 vs..374 for the .380

 

But the extra 1mm of case length should be obvious - are you sure it's not european .380, labeled as 9mm Kurz?

 

 

Edit: oops I typoed 9x19, now fixed, other info is correct per Hornady 9th; thanx roverboy.

Edited March 19, 2013 by ttocswob

[roverboy]

I think Tennjed is talking about 9x18 makarov brass.

[Jonnin]

it would probably work if it would chamber.  9x18 is wider than 380 by just enough to be a problem.   You can fire 380 brass in a mak, but this is a reverse issue, the gas blowby is bad for accuracy and damages the gun over time.  You probably could put a 9x18 bullet in there, and have a short makarov, the load data and bullet weights are close.  Brass in and of itself is not going to cause a kaboom, the issue would be how it was loaded and any bore obstructions created from it.

[Jason in TN]

Find one of those hiding in my 9x19 brass from time to time.

Jason