9mm Case Trimming

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You measured a 9mm? Wow... Isn’t there some THR Reloader Of the Month award we can give you?
I keep tabs on a lot of reloading things, but 9mm case length is not one of them, yet.
 
cfullgraf said:
Just a thought, aren’t there some 9x19 cases with a stepped interior?

If so, could the trimmer guide be stopped by the step?

I’ve never seen a stepped case but comments come up about them once in a while.
Click to expand...
The base of the LEE trimmer is only about 1/8" or so tall, so it doesn't go into the case far enough to hit the 'step' inside those cases.
 
I gotta be honest, I have never heard of a guy who trimmed 9mm. I rout the primer pockets and I thought that that was my OCD max.
 
KentM said:
You don't specify which Lee trimmer you are using, but if it is the Quick Trim (either powered or hand cranked) you probably just need to remove the spacer ring. It is a free-spinning knurled ring below the black adjustment ring, and Lee says to ADD it for cases longer then 1.25". Well, it comes with the ring already installed so the instructions should say to REMOVE it for cases shorter than 1.25", which would include the 9mm Luger. Removing the spacer will also give you access to the aforementioned ball. Simply grasp the shaft above the cutters in one hand and twist the top portion (above the adjustment ring) with the other. If you have the powered version this will be where you attach the drill. If you have the hand crank version, grab the crank itself. If it won't unscrew you might want to wear a leather glove in the hand holding the shaft, but trust me, it does screw off. That should fix your problem. I just tried installing the spacer ring on mine, just to see, and it behaved exactly as you described.
I don't think removing the ball is appropriate in this case, since Lee says that is for when the case neck is too small for the die. Oh yeah, and the cases should be resized before trimming or they could be a tight fit into the die.
Click to expand...

welcome to thr kentm.

murf
 
So, I buy once-fired by the bucket from a ccw trainer. I sort 'em out and then run what I keep through a case gauge. Yes, I've trimmed those that showed high - maybe 50 in, jeeze, A LOT. I keep 'em in batches and never look at case length again. One can never have too much brass or too many shotgun shell hulls.
 
I've read in a few different places that semi-auto cases do shrink in length with use. One person mentioned that the repeated set back against the bolt case can "shrink" the extractor groove. But I can't prove or disprove the theory and don't give a rat's patooty. None of my 9 semi-auto pistols get/need trimmed brass...
 
mdi said:
I've read in a few different places that semi-auto cases do shrink in length with use. One person mentioned that the repeated set back against the bolt case can "shrink" the extractor groove. But I can't prove or disprove the theory and don't give a rat's patooty. None of my 9 semi-auto pistols get/need trimmed brass...
Click to expand...

It's true. No doubt about it from my end. Autos seat on the case mouth and the brass gets hammered back. The SAAMI chamber specs are .754 minimum and .776 maximum, and I haven't seen any brass near .776, but I have run across a few pieces up over .761. I trim the extra-long in a batch more to keep crimps running somewhere near a steady length.
 
I've had it written into my living will that if a family member catches me trimming 9mm or 45 Auto they are to hit me in the back of the head with a blunt object until I stop breathing
 
DMW1116 said:
I chucked the Lee guide for 9mm into the trimmer
Click to expand...

I didn't even know they made such a thing for 9mm.

I have trimmed brass to be used in a revolver so that I can get a consistent roll crimp, but I've only ever done that once. Never trimmed semi-auto pistol brass.

-Jeff
 
NMexJim said:
It's true. No doubt about it from my end. Autos seat on the case mouth and the brass gets hammered back. The SAAMI chamber specs are .754 minimum and .776 maximum, and I haven't seen any brass near .776, but I have run across a few pieces up over .761. I trim the extra-long in a batch more to keep crimps running somewhere near a steady length.
Click to expand...
Are you certain about these numbers? I thought it was .754 max and .744 min. But I confess to not understanding engineering drawings.

Any way, and I know this is an older thread, but yesterday at the range one of my 9mm rounds wouldn’t chamber in my WC CQB so put it in my pocket and took it home.

At home I tried my Hornady case gauge and the loaded cartridge wouldn’t fit there either. Took it apart and the case alone wouldn’t fit the gauge. Measured it at .762”

It’s a PPU. So I dug around and found several other PPUs and most measured greater than .754”.

I’m not about to buy the equipment and start trimming a few PPU 9mm cases.
 
NMexJim said:
The SAAMI chamber specs are .754 minimum and .776 maximum, and I haven't seen any brass near .776, but I have run across a few pieces up over .761.
Click to expand...
CQB45ACP said:
Are you certain about these numbers? I thought it was .754 max and .744 min. But I confess to not understanding engineering drawings.
Click to expand...
One of you is talking about SAAMI chamber dimensions and one is talking about SAAMI cartridge dimensions. SAAMI chamber headspace dimension measured from breech face is .754-.776". SAAMI case length is .744-.754". Both of you are correct.
 
I have never trimmed a pistol brass in 30+ years reloading. In fact I don't even have the trimmer mandrels to do it. The only straight walled brass that I have had reason to trim is 30 Carbine. I figure if it worked enough to fire once then load em up and repeat.
 
I've only done a few hunded 9mm cases, but do measure them after sizing, just to see. Still haven't found one too long, but a good percentage maybe 10% were too short, so - I culled them into another container to figure out what to do with them later.
 
9mm no but I have some old cbc 357 brass that has grown on me, next time I shoot them I'll measure them. I noticed when they go into the crimp die they crimp a little weird like they are too long.
 
I just went through a pile of range brass and measured some randomly. I did find some that were too short but apparently the still shot OK so if I was you and had some culled out I would load them up to use where you could not recover your brass, use them and leave it at that.
 
I've never measured or trimmed any pistol brass (except 460S&W).

Maybe this is why I haven't had any over-COAL 9mm case issues, as I trade/scrap my unfavored (is that a word?) headstamps including PPU.
CQB45ACP said:
At home I tried my Hornady case gauge and the loaded cartridge wouldn’t fit there either. Took it apart and the case alone wouldn’t fit the gauge. Measured it at .762”

It’s a PPU. So I dug around and found several other PPUs and most measured greater than .754”.
Click to expand...
 
After measuring hundreds and hundreds of 9mm and not finding a single one that was too long, I stopped.
 
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