9mm case neck too skinny to cut..

[bulpup 98]

I have about 350 brass pieces that I have been cyling through my press. Out of those 350 there are some 20 or so that just will not accept the Lee case trimmer. This is the trimmer/sizer that is to cut to the exact 9m Luger size and has a metal post at the blade end that, as far as I know, should be at the diameter expected for the 9mm luger case mouth.

 

I trim after popping the spent primer, which is built into the Lee case sizing die. Most have no issue but I just can't figure out how a spent pistol case can be too small a the opening.

 

Any ideas why or what I can do to fix that? I have tried running them through the sizer twice and got nothing.

[Pew Pew Plates 358]

...why are you trimming 9mm?

 

Never heard of anybody doing this. Its really only neccesary on bottlenecked/rifle stuff

[Maksim 1,504]

what glenn said.

[Old School 611]

What Glenn and Maks said.

 

Just for the record...9mm headspaces on the case mouth and never gets shorter than it's original length.

 

So...if it chambers the case length is within spec.

 

Load your rounds and run them through here and you'll never have a problem: http://www.dillonprecision.com/#/content/p/9/pid/25580/catid/3/EGW_Chamber_Checkers

[djg0770 481]

Let's put aside the issue of trimming pistol brass and instead focus on the issue...

 

The brass in those suspect rounds is a few thousandths thicker than your typical brass. I've found this with 38 special cases too. In some cases I can narrow it down to a specific mfr.

[bulpup 98]

(To all, I changed the misleading title. It isn't that the case is too short, the mouth is too skinny; as in, the inner diameter is so small the cutting tool does not fit inside.)

 

 

I dont get much brass off of them when I do, but I am doing a little of my own familiarization with brass and metals and such. The 350 cases I have have been shot out about 3 times each and they are starting to show just a little bit of rattiness. A good 20% have extra to trim, some have had a few nicks in them that get cut right off if the length isn't right. I have been reloading out of a box of 2000 Ranier Leadsafe rounds and I can really see the difference in the "lead-ness" of the round as compared to the first 250 JHP I reloaded. It is so soft that if the neck is to tight I get an imprint in the nose of the round from the bullet seating die. So I have an interest in making the necks at least uniform in the inner diameter.

 

So for me it is more to make sure all are being reset to a normal everything while I work on my loads, crimps and routine. But, Dan, what do you do when you get one of those small one's? I was thinking a wooden dowel?

 

Old School, I am not sure I get how that checker works. Does that check with a round in or out of the case?

 

And on a side note, since many seem to dismiss cutting a 9mm case, what do y'all feel about chamfering? I am not even sure I understand what that is suposed to do.

[Pew Pew Plates 358]

Thats another step you leave for the rifle brass.

 

Case prep for regular pistol rounds consists of cleaning it. thats it. Chamfering, uniforming primer pockets, cleaning primer pockets, trimming, etc etc is stuff you should not bother with on pistol brass unless MAYBE you are benchresting it at 100 yards +

[Socom 19]

...why are you trimming 9mm?

 

Never heard of anybody doing this. Its really only neccesary on bottlenecked/rifle stuff

 

I agree word for word!

[zoid 24]

Man if I had to do anything more than tumble handgun casings I'd just forfeit reloading all together.

I'm that lazy. I only reload so I can shoot more. It is kind of enjoyable for me when everything is

going right.

[Old School 611]

Old School, I am not sure I get how that checker works. Does that check with a round in or out of the case?

 

 

That checker is a block with 7 minumin dimension chambers cut in it. You take your finished rounds and run them through the block and you assure yourself zero defects. When we were going to a match I'd remove the barrel an run them through there. This is much easier and you just do it tactily.

[Col. Mortimer 11]

I may be one of the biggest brass hogs (whores) out there but when a piece of brass, especially high pressure rounds like 9mm or .40S&W, looks tired, I toss it. There is so much 9mm brass out there that trimming just doesn't make any sense.

[tony357 386]

I trim all my 9mm you would be suprised how many are too long by alot!! I noticed this during reloading on the crimp stage you can feel it over crimp when it is too long.

 

trim before you resize that is how i do all mine. Then tumble afterwards.

[raz-0 1,259]

Straight wall brass gets shorter when you resize it, unlike bottle neck cartridges. You don't need to trim it, and you should never trim before resize. Think about it you trim to a certain dimension, and then you change that dimension by sizing.

[tony357 386]

Straight wall brass gets shorter when you resize it, unlike bottle neck cartridges. You don't need to trim it, and you should never trim before resize. Think about it you trim to a certain dimension, and then you change that dimension by sizing.

 

In theory, i have measured after sizing and have not seen a diffrence even if it is .001 or 2 it is alot better than crimping a case that is .015 longer than the rest..

 

The length of the cartridge has to start somewhere, no diffrent than taking a once fired case and resizing it does not matter if you cut to length before or after.

[djg0770 481]

see related thread here: http://njgunforums.com/forum/index.php?/topic/27026-problem-with-some-38-special-cases/page__st__30

 

In trimming 38 spc brass, I've found (after resize/deprime) what you are finding with 9mm, that the lee case length gage sometimes just doesn't want to go into some cases.

 

With respect to 9mm though, and with the commonality of the brass, you could just toss those cases rather than trying to fix a problem that doesn't need to exist.

[lunker 274]

Straight wall brass gets shorter when you resize it, unlike bottle neck cartridges. You don't need to trim it, and you should never trim before resize. Think about it you trim to a certain dimension, and then you change that dimension by sizing.

 

+1. Pistol brass is the opposite of rifle brass. It does not get longer with use. Chuck it when it gets too short. The brass Tony is trimming came that way from the factory. It wasn't shooting that made it longer than it should be.

[bulpup 98]

Good stuff Dan. That other thread answers a lot.

 

Otherwise, I had honestly not considered the effects of picking up brass at the range. I do find that I want to make sure my new brass is not longer than the rest of the batch I have, and in doing this "level setting" of all my brass I just completely forgot that I keep getting more brass off the floor than I had arrived with. At the moment though, the only thing I own that indicates that the mouth of a case is too small (or rather, smaller than the rest) is the Lee cutter.

 

Somehow I had convinced myself that brass I shot was getting tighter in the mouth. I guess it is most likely just new brass added to the batch.