[ARCHIVED THREAD] - 9MM Case Length

Posted: 6/12/2017 10:19:00 PM EDT

I think I know the answer here as I asked about this concerning .223 cases. My Speer 49th edition shows the length of a 9MM Case to be .754 in the drawing and .751 trim to length in the notes. So far I've got a great deal of the cases between .751 & .754. For grins, I checked some of the prepped cases I just finished wet tumbling and they are around .747. How does this happen, & does this mean I can't safely use the .747 cases? BTW I am referring to the 9X19 MM. They will be shot out of a S&W 5906 & a Keltec P11.

Posted: 6/12/2017 11:01:48 PM EDT

[#1]

No one measures or trims 9MM - Pistol brass generally shrinks as you shoot it - you'll lose it before it's unsafe to load.

Posted: 6/12/2017 11:12:56 PM EDT

[#2]

Semi auto pistol cases are not generally trimmed. 9mm, 45 ACP, ect.

Use them as is.

Bottle necked cases (223) will grow and will need to be trimmed as needed.

Posted: 6/12/2017 11:54:52 PM EDT

[#3]

I have had a fair bit of variability in case lengths depending on brand. Over the 10 headstamps I have to work with the variability is 0.02", so my press is set to make 1.150" with Winchester cases, but the variability is between 1.140" to 1.155", roughly.

Posted: 6/13/2017 1:47:47 AM EDT

[#4]

SAAMI spec for 9 mm Luger cases is 0.744" to 0.754".

So, yes, in a properly chambered barrel, 0.747" is okay to use.

Posted: 6/13/2017 9:09:14 AM EDT

[#5]

Lymans 50th says the same thing. I have never reloaded 9mm so never paid much attention to it. Guess I will go back and reread the front of the manual.

[ARCHIVED THREAD] - 9MM Case Length

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[ARCHIVED THREAD] - 9MM Case Length

[ARCHIVED THREAD] - 9MM Case Length