9mm Brass: Better to trim or sort by headstamp?

Trim 9mm?
Heck I don't even measure it.

Life is too short

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Sort by headstamp, well other than tossing steel/Al and the ones with the stupid internal ledges, I reload it all.
( 9mm with crimped primer pockets goes to the recycle can, I have plenty of .223 to remove crimps from.)


I do case gauge all 9mm ammo I use for matches since I use scrounged range brass.

What is right for me may not be right for you.
If you have the time do a couple tests for vel (if you have a chrono) and accuracy.
1 Mixed headstamp vs same headstamp
2. Trimmed vs non trimmed
Once you have the results you can decide if it is worth sorting or trimming.


If I was loading SD loads (I prefer to use factory ammo for SD) I might sort by head stamp.

No measure, no trim, no sort. Load, point shoot. Pick it up and start over.

I'll sort, looking for fed, win, rem, any cci products, cbc, LC, perfecta, and a few other common ones and everything else goes in the soon to be range ammo pile.

You’ll have to decide for yourself if you have to satisfy any proclivities.
I wet tumble, only because nice shiny brass makes me shoot better, load it, gauge it, and shoot it. I use the shockbottle 100 round gauge and it doesn’t take to long for this step. Good luck.

9mm, 9mm short, 7.65mm: the only things I am measuring are the powder and the C.O.A.L.

FWIW, I've loaded a lot of 9MM since 1967, and to my recollection, have never trimmed 9mm cases. I don't recall feeling the need to sort either, other than perhaps brass from nickeled cases, etc. I do understand trimming and/or sorting, if one so chooses in an effort to achieve brass with the most consistent length, case capacity, etc.

Just out of ballistic curiosity, I've measured a fair amount of 9MM brass over the years, and have rarely found a case as long as the industry standard .754". I've also measured headspace in a number of 9mm pistols, from a variety of manufacturers. The average headspace was just over .761". So even with that rarely encountered .754" 9mm case, there is more than enough room in the average 9mm chamber to allow the cartridge to fully chamber.

The tightest 9mm semi-auto headspace I've measured was .748". Even that pistol with less-than-factory-standard headspace functioned literally 100% reliably with any and all of the 9mm ammunition I used in the gun.

As I indicated, I don't trim 9mm cases

With 9mm I get all my brass from the range, so I grab all I can and get home. It gets deprimed, swaged, wet tumbled, resized, primed, and stored. I haven’t measured a pistol case in 30+ years.

gonoles_1980 said:

I currently sort by headstamp, though some headstamps are a little older. I'm making the assumption that the same headstamp is close enough in size. I only want to trim or sort. Curious what do you guys do?

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I don't trim but I do sort by head-stamp if I'm making a special load, and I do separate nickel from yellow brass (mostly), and by my own method of assessment: yuk!-toss, dull, not-so-shiny, kinda-shiny, shiny and oooh pretty!

I don't trim 9mm for any reason. I do sort by head stamp just so the internal volumes are the same in my batches. My 9mm brass could stand to be chamfered due to rotary tumbling, but the only time I do that with 9mm is when I'm using coated bullets, so the nicks and burrs don't cut the coating up when seating a bullet.
I use a gauge also but most all of my rejects are from nicks on the rim at the head of the case for someone's extractor. So I just load them then dry tumble them before running them through the gauge. That gets most of the nicks off the rims, then I run them through the case gauge and have very few rejects.

I will add that I do seperate brass from the nickel and save the nickle as a reserve supply. Don't really have a reason for this though, just do it.

I sort & load by head stamp. The plus or minus .002/.003 I got loading mixed head stamps would drive me crazy. I can handle the very minor difference in OAL of brass with the same head stamp

I deprime, wet tumble, and oven dry/inspect. I then sort by head stamp and weight. I also segregate nickle-coated cases because (1) I read (somewhere) they can't be reloaded as often and, (2) I reserve them for SD rounds.

The SD rounds get much closer scrutiny......

I’ve occasionally had a 380 get into my 9mm by accident and get sent thru the press. They went bang.

I’ve never had a piece of 9mm brass that was too long.

I sort by headstamp.

BJung said:

I sort by headstamp.

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.Me too, and I am not sure why. Maybe it is because I have the time and maybe because I focus on a loading a very few headstamps and save the others for armageddon.