Very strange issue with 9mm brass and Lyman case gauge...

[the count]

I have been reloading 9mm for years now. Got myself a Lyman 9mm case gauge recently and have experienced some strange things...

1) I use a LEE small base 9mm die (yes there is such a thing). Most of the resized brass will sit just on top of the gauge, some will go right through and some stick out quite a bit (see pictures A and B). Seems to be no rhyme or reason as to which do or don't. All will work flawlessly through my Glock 19, Keltec Sub2K and SIG. Only the CZ75 seems to be somehow finnikey and will on occasion cause hiccups as the chamber appears to be tight.

2) Really weird department. The round in pic A went right through the gauge yet sticks out more (Pic D) in the CZ 75 chamber than the round in pics B and C which sticks out a lot with the gauge....?

PS Have tried the same die in my LNL AP progressive press and a Lee turret press. Same results. With the LNL the die needs to be screwed in almost all the way for it to touch the shell holder.


Whats the story here? I think I once read about a pretty expensive device that forms the entire 9mm case to factory spec.

PIC A

PIC B

PIC C

PIC D

 

[Blue68f100]

Check for nicks and burrs on the brass. Paint the round with a marker and see where it's rubbing.

Is this once fired from your guns or range pickup? You may have a bulge at the base. Marking it up will show where..

 

[the count]

Check for nicks and burrs on the brass. Paint the round with a marker and see where it's rubbing.

Is this once fired from your guns or range pickup? You may have a bulge at the base. Marking it up will show where..

Usually a mix of other guys brass and my own.

 

[Jesse Heywood]

Take a marker and color the outside of a case that doesn't fit. Then put the round into the gauge until it stops. When you pull the round out of the gauge the marker will be gone where there is interference.

 

[Walkalong]

The gauge has nothing to do with the chamber. Lots of fat 9MM chambers out there. I have an EMP with a SAMMI minimum chamber (.391 at the base) so I use a Wilson case gauge to check all my sized brass. If it passes the gauge it will chamber. Occasionally one will stick out as far as yours, but most that fail stick out 1/8" or less. These same brass will fall into my other 9MM chambers.

Scrap the ones that fail the gauge, and load the rest.

 

[the count]

Take a marker and color the outside of a case that doesn't fit. Then put the round into the gauge until it stops. When you pull the round out of the gauge the marker will be gone where there is interference.

Did the marker thing with a couple rounds. And the rub off was exactly where the case stopped entering the gauge as in pic B. I am beginning to think that the issue has to do in which gun the round was fired from....as in a lose chamber the very end of the case might expand more which even a small base die will not resize.

 

[the count]

Thanks Walkalong...

once again I realize that with reloading the only constant is that there is no constant

 

[peels]

I think you are correct that brass coming out of one of your guns is bulged at at the base. I noticed some brass with a slight bulge will cause the brass to skew to one side and it will either not fully enter the case gauge or it will catch on the rim. Some will go all the way in if forced, but some will stop dead at the rim. But all of them will still fully chamber in my 9mm.

One thing to check is to make sure you have your dies adjusted properly. With the FL (or small base) die fully inserted, raise the ram all the way (with shell holder). How much gap do you see between the top of the case holder and the bottom of the die? I was having some problems with undersizing 9mm brass until I realized that I grabbed the wrong shell holder (grabbed a Lee one, while the dies were adjusted for a Redding one...oops!).

 

[the count]

I think you are correct that brass coming out of one of your guns is bulged at at the base. I noticed some brass with a slight bulge will cause the brass to skew to one side and it will either not fully enter the case gauge or it will catch on the rim. Some will go all the way in if forced, but some will stop dead at the rim. But all of them will still fully chamber in my 9mm.

One thing to check is to make sure you have your dies adjusted properly. With the FL (or small base) die fully inserted, raise the ram all the way (with shell holder). How much gap do you see between the top of the case holder and the bottom of the die? I was having some problems with undersizing 9mm brass until I realized that I grabbed the wrong shell holder (grabbed a Lee one, while the dies were adjusted for a Redding one...oops!).

Yep, the die is touching the shell plate. With Lee dies in a Hornady LNL press this usually means screwing it in until only the last thread or two engage the securing nut. It also looks like some brass is more likely to not fully size...ie S&B almost never passes the gauge test while Winchester seems to be extra reliable. Go figure.

 

[sexybeast]

9mm is a tapered case. There is not reason for any "bulge" at the base not to be resized/sized down
I don't care what it was fired out of, when its resized it should fit in your gauge. I get all kinds of brass fired out of all kinds of guns, some really swelled out. My Lee carbide dies sizes all of them fine. Primer pocket problems yes, sizing to spec no.
Try another sizing die.
I have no idea what a small base die is though. What is it?

 

[Rushthezeppelin]

I have no idea what a small base die is though. What is it?

From Midway description (google is your friend, well sorta ):

Lee U Carbide Small Base Sizing Dies are great for reloaders looking for ultimate feeding reliability in their handgun. These dies undersize brass between .002" and .003" smaller than other Lee Carbide Sizing dies. Ammunition with undersized brass cases will chamber each and every time it is loaded out of a magazine giving reliable chambering each time a round is stripped out of the magazine or loaded into a cylinder. Competition shooters rely on having ammunition that will feed and chamber each round of ammunition as it is stripped out of the magazine. One of the other benefits reloaders have reported when using Lee U dies is increased consistency and accuracy in loaded rounds because these dies help increase and provide more consistent neck tension on loaded bullets.

 

[sexybeast]

So it actually undersizes the brass. I see no reason why you are having problems if the die comes dow to the shell plate. I'm stumped!
I've never had this problem and I size and load 15k of 9mm each year with mixed range brass.

 

[[email protected]]

The lee undersize die will also help with neck tension wihen loading thin wall brass (RP) when using jacketed bullets.

 

[the count]

So it actually undersizes the brass. I see no reason why you are having problems if the die comes dow to the shell plate. I'm stumped!
I've never had this problem and I size and load 15k of 9mm each year with mixed range brass.

That's why it's a riddle wrapped in a conundrum!

 

[mstreddy]

Count, I have a similar issue with some brass - not using a Wilson gauge but using my Lone Wolf very tight chamber barrel. For me the R-P and CBC brass is tougher to resize and I had to adjust the die down further for it to work the brass enough to fully plunk into the LW barrel. I am using a Lee sizer, but I also noticed this in the Hornady sizer. As to the Lee being short for the LNL, try turning the nut upside down or attaching it from the bottom as some suggest. Use your chamber for the test and if they work there, disregard the Wilson gauge.
CZ 75s tend to have shorter chamber/throat so that may be in play as well in your case. And your OAL or not removing the flare might be a culprit too.

 

[Otto]

All will work flawlessly through my Glock 19, Keltec Sub2K and SIG. Only the CZ75 seems to be somehow finnikey and will on occasion cause hiccups as the chamber appears to be tight.

If you are new to CZ's you will soon find out that the position of the rifling requires very short OALs. Typical CZ OALs will range from 1.040 to just under 1.100" unless you are using the standard ogive shaped bullets.

I think I once read about a pretty expensive device that forms the entire 9mm case to factory spec.

That would be a roll sizer called a Case-Pro 100.

 

[the count]

If you are new to CZ's you will soon find out that the position of the rifling requires very short OALs. Typical CZ OALs will range from 1.040 to just under 1.100" unless you are using the standard ogive shaped bullets.


That would be a roll sizer called a Case-Pro 100.

On a side note...while I do have a several very good pistols my carry gun is a Glock (9mm or .45) because they will chamber and fire just about any round. Plus no safety or decocker etc. to think about in an emergency situation. And I am not even a fan of the Glock trigger! Sorry for sidetracking here ;-)

 

[sexybeast]

The Count wrote:

That's why it's a riddle wrapped in a conundrum!

Yes it is. I use that same exact Lyman case gauge. Also use Lee dies and every completed cartridge with all the different bullets I have used goes into that gauge and I have not ever seen this. I would try another sizing die and see if that changes anything.
As I said I load a whole bunch of 9mm with all different brass and this is something I have never seen.

 

[the count]

LEE bulge buster kit - but does not work with 9mm

This is interesting. From the Lee web site:

"NOTE: 9mm cases are not able to be used in the Bulge Buster because it has a slightly tapered case and the rim is not completely flush with the case."

Didn't know that. And after more detective work it does appear that certain brands of brass are 'better' than others. Winchester always passes the gauge test, S&B almost never does, FC is iffy.

And like somebody said above, the Wilson case gauge is not a chamber gauge, so in the end only your barrel is the final judge.

 

[Wil Terry]

OBVIOUSLY, you are getting variations in the sizing of the brass. IF the dies are tight and correctly set in the press the only variation can be the stroke of the ram. NOW, all you have to do is figure out what is causing that variation. My guess....springing in the press from different pressures needed to size different sizes of the fired brass.

 

[Walkalong]

I picked a few 9MM cases that failed the Wilson gauge out of the scrap bin. This is a typical failure, although if they go all the way into the gauge, but will not fall out from their own weight when the gauge is turned over, I toss them as well. Some failures will stick out a little farther, but I do not remember any that failed nearly as badly as the pic from the count's post. I would guess I have had a 10 to 15 percent failure rate on sized range brass. After that, shooting my reloads, the failure rate goes down to nearly nothing.

I have two 9MM sizers, a Redding and a Lee. (Well, I had a Hornady nitride sizer years ago, but the nitride wore off right away and I replaced it with a Lee carbide sizer.)

The Redding leaves a noticeable ridge at the bottom of the area sized because the carbide ring is straight and 9MM cases are tapered. Because of this, the further down you size, the worse it gets. The Lee does not, as the carbide ring has a slight taper. Neither one sizes any tighter than the other one, not at the base or the case mouth. I use the Lee because it leaves the cases much nicer looking, and I feel it sizes more concentric because the ridge left by the Redding tends to be on one side. And it simply looks better.

As I posted earlier, these failed cases will drop right into my other 9MM chambers, but will jam in my EMP with its tight chamber. Factory ammo and reloads that fit the Wilson gauge run like a Swiss watch in it. .3915ish will run, but .392 will jam up in the camber. If the cases pass the Wilson gauge the way I use it, they are a minimum of .391 near the base.

 

[longhill]

Two things I noticed on my 9mm reloads not fitting the case gauge.
Besides making sure that the sizing die is
1. Not have enough crimp, causing the case not to go into the gauge completely.
Easy fix, lower the die to get more crimp.
2. The base of the case is dinged by the ejector or had a burr.
To confirm if its rim is deformed. The base should fit backwards in the case gauge.
If not, my three fixes. CasePro 100 to roll size the base of the case back to factory specification, or a case bulge buster(yes, Lee Precision make one for the 9mm, special order, works great by the way), lastly put the case in a drill and use a flat file to get rid of the burr. if any of those three don't work, its time to toss the case.
Just some suggestions, YMMV

 

[gamestalker]

Since you don't know for certain what loads the range pick ups had fired through them, it could be the result of high pressures bulging them. And on that note, what are the specifics of the load you are running? I run some pretty snappy loads and will occasionally experience some bulging as a result.

Um, small base die for 9mm, didn't know there was such a thing. Maybe someone makes a bulge buster for 9mm too?

GS

 

[Walkalong]

I run some pretty snappy loads and will occasionally experience some bulging as a result.

See my 10 to 15 percent comment.

I never have problems with loaded ammo if the sized case fit the gauge prior to loading.

 

[longhill]

Order the Lee Bulge Buster Kit and a Lee 9mm Mak Factory Crimp Die. This die will only touch the rim of the case and will iron out the bulge.