Author Topic: Minimal 9mm brass length  (Read 980 times)

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Offline Rcher

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Minimal 9mm brass length
« on: May 08, 2020, 12:12:46 AM »
I sorted my brass today by manufacturer to prepare cases for my first reloading. Measured brass length for one time shoot brass and it is between 0.740" and 0.743". After resizing it became 0.747"-0.749".
I know that SAAMI maximal length is 0.754", but what about minimal?

Offline painter

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Re: Minimal 9mm brass length
« Reply #1 on: May 08, 2020, 07:27:00 AM »
SAAMI spec is .754 - .010.

That would make minimum .744.
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Online Wobbly

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Re: Minimal 9mm brass length
« Reply #2 on: May 08, 2020, 07:58:03 AM »
• All the SAAMI specs are online.... HERE.

• That Min/Max number is really the number for newly manufactured brass to properly fit the chambers of all 9mm guns in the US. For reloading purposes it can even be a little shorter, but when you get shorter than 0.744" the case is suspended more by the extractor than by the end of the chamber. Not an optimal condition, but it still works.

There's a theory/ conversation/ general belief that handgun brass gets shorter over it's life. If so, I must have some of the shortest brass in recorded human history. All my brass goes from my home range, back to my reloading cave, then back to my range. I don't have a piece that's not 15 years old, a lot of it nearing 25. But, case length measurement has never been one of my reloading criteria.

So you can measure your brass length if you want, but I wouldn't be throwing away any brass because it was, for instance 0.742". Length is simply not one of the major reloading criteria. Throw it out if it splits or cracks. Throw it out if you can push a primer out with a wooden toothpick. Otherwise, reload it one more time.

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Offline recoilguy

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Re: Minimal 9mm brass length
« Reply #3 on: May 08, 2020, 10:45:22 AM »
I have been reloading for a while now and I have not ever measured the brass length of my brass and like Wobbly I have some that are almost as old as my kids.
My kids are out of college. I also have some brand new stuff as well. When it cracks or bulges I throw it out and I don't throw a lot away.

Good luck, have fun. be careful.

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