9mm cases splitting

[John McCorkle]

Hi all

I've reloaded 9mm for a while with boolits and am only now taking the advice of so many here and using a larger expander that reaches deeper into the case body to make sure the boolit isn't swaged while loading... hoping to see good results but it's seems a good practice for cast boolits with many/most having great success.

I'm noticing several split cases in this operation (doing these on a single stage press at the time just to get a feel for it and glad I am...I can absolutely feel when they split) using Lee does with a 38sw powder through expander I polished up the mouth just a touch with 1000 grit followed by strop paste to really smooth/polish it up but didn't take any off the diameter of the expander stem when doing so.

I know brass has a lifespan and I'm certain the cases splitting aren't on their first reloading...but wanted to poll you all to see if you guys are seeing the same thing?

Getting splits on 1-2 out of 100...not a ton and I've got a ton of 9mm sonit isn't causing a problem per se but I found it interesting, never seen this in 9mm at this rate. I know it is due to the larger and deeper expansion but curious of your experience with this?

Sample of cases below...I guess I've expanded 2k by now so I'm seeing a pattern258089

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[tazman]

Interesting. I don't believe I have ever split a 9mm case during reloading.

[Walks]

Me neither, weird.

I use a 45yr old Lyman Die set with a
M-Expander die with a .3555 insert. The sizer is a 1980 Carbide with a C&H taper crimp die from about 1984.

I use Lyman #356402 or Lee # 356-125-2R
sized to .356dia, never had a split case that I can recall.
Shooting this ammo in Walther P-4, P-38, 1921 Commercial Luger, Browning Hi-Power, Glocks with Wolf bbl's and Ruger 9mm cylinders.
Loaded over max Bullseye.

I've also shot it in Sigs, S&W's, Beretta's, Colt AR's, Marlin Camp 9's and a bunch of others that I can't remember.

I only use American Commercial or G.I. cases and a few Fiocchi.

Never range pickup. Those I just sell when I have enough to make it worth while.

[unclemikeinct]

Be thankful those split before loading/firing. I've lost 3, 9mm cases in forty years of reloading. When they split on firing. it is not pleasant. I have never had a 38 special behave like that.

[ioon44]

Are all the split cases the same head stamp?

[John McCorkle]

Be thankful those split before loading/firing. I've lost 3, 9mm cases in forty years of reloading. When they split on firing. it is not pleasant. I have never had a 38 special behave like that.I've seen them split in firing before but it's typically a small fissure on the side maybe 1/8th below the mouth and about a 1/16th long. When it's a crack in firing it's shown carbon scoring in an hour Glass shape in relation to the crack as the gasses vent but it's never harmed the gun that I know of...it's a bit louder and can't be good for the chamber but never seen any negative effect

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[John McCorkle]

Are all the split cases the same head stamp?No it's all over the place, Speer, Winchester, sig, Remington Federal...all of em. Wish there were a pattern

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[Bashby]

I split a few during my last session. I am using a 38sw expander in Lee dies also. IIRC, I had it set pretty deep. 258101

[toallmy]

I use a lee 38 S&W powder through expander plug and don't have that problem , or at least not yet .

[hermans]

John, do you have access to a micrometer? If you could measure the size of your expander plug, maybe that can shed some light on the problem?

[RydForLyf]

Very interesting. I'm looking forward to how this turns out. :popcorn:

[John McCorkle]

John, do you have access to a micrometer? If you could measure the size of your expander plug, maybe that can shed some light on the problem?Looks like a .3568-357 ish https://uploads.tapatalk-cdn.com/20200306/71874bbb301ebd1f69458c8226ab49b0.jpg

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[John McCorkle]

John, do you have access to a micrometer? If you could measure the size of your expander plug, maybe that can shed some light on the problem?Also this, this AM I am processing through a batch of 9mm that was previously expanded with the original plug (original Lee 9mm powder through expander - I pre prepped alot of brass in stages)

These have yet to give me a split...I've only expanded a couple hundred so sample size is small and not ready to say it's not giving me any problem period....but it's interesting

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[Burnt Fingers]

Wow! That's not a split, that's a tear.

I've found a few split cases while reloading. Not many 9mm, mostly .45 ACP. It's always a small vertical crack at the case mouth.

Something is going on in your process. Try some Hornady One Shot sprayed into the case mouth.

[John McCorkle]

Wow! That's not a split, that's a tear.

I've found a few split cases while reloading. Not many 9mm, mostly .45 ACP. It's always a small vertical crack at the case mouth.

Something is going on in your process. Try some Hornady One Shot sprayed into the case mouth.Sort of what I thought, it's surprising and I've never seen anything like it before. I haven't heard others who have either.

I think I could prob use one shot or any number of lubes but I don't think others here do/have and I'd like to not make 9mm an even more pia than it is especially when loading in bulk.

My real concern is that with this issue popping up I don't think I can reload on a progressive press at all...

Would love to find that root cause you mentioned

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[Dusty Bannister]

Is the new expander plug as well polished as the original? Is it too loose or not centered in the die body? Maybe too sharp on the end of the plug so it does not enter the case mouth smoothly?

[Murphy]

I've been reloading nearly 40 years and that's a new one to me. I don't believe it's a case problem. I'm not sure how deep your expander is set, but that would be my first suspect. Please keep us informed when you discover the problem. It will be interesting to know what is causing it.

Murphy

[JonB_in_Glencoe]

Have you measured case length of the split/torn cases?

[John McCorkle]

Is the new expander plug as well polished as the original? Is it too loose or not centered in the die body? Maybe too sharp on the end of the plug so it does not enter the case mouth smoothly?So originally when I first got the plug the "feel" of it was very sharp... meaning, entering the sized brass case mouth would result in a snag fairly often ...so I took it out and slightly reprofiled the leading edge of the expander with 1000grit...may not have actually reprofiled it at all it but that was my intention...then hit it with a polishing compound that makes it very very smooth. What was and still isn't polished well is the body/shaft of the expander stem and I can feel the tooling marks on the stem as the cases slide onto and off the expander...again all of this is by feel but I can definitely tell

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[John McCorkle]

Have you measured case length of the split/torn cases?No but not sure I would get a consistent read with the amount of tear/rupture on them after they split

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[JonB_in_Glencoe]

you maybe correct?
Obviously one side of the diagonally torn case mouth is long, but the other side "may" give a reading worth talking about. I would measure several and get an average...to see if it's longer than they should be.

[JonB_in_Glencoe]

So originally when I first got the plug the "feel" of it was very sharp... meaning, entering the sized brass case mouth would result in a snag fairly often ...so I took it out and slightly reprofiled the leading edge of the expander with 1000grit...may not have actually reprofiled it at all it but that was my intention...then hit it with a polishing compound that makes it very very smooth. What was and still isn't polished well is the body/shaft of the expander stem and I can feel the tooling marks on the stem as the cases slide onto and off the expander...again all of this is by feel but I can definitely tell

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That should feel smooth.

[John McCorkle]

That should feel smooth.When I ordered from Lee I got two, I may try to polish the tooling marks smooth on this one without changing the diameter much if any and see if that makes a difference.

My larger concern is that I don't have a lathe and don't want to polish away material and make the stem wobber jawed, oblong or otherwise off center...

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[pastera]

When I ordered from Lee I got two, I may try to polish the tooling marks smooth on this one without changing the diameter much if any and see if that makes a difference.

My larger concern is that I don't have a lathe and don't want to polish away material and make the stem wobber jawed, oblong or otherwise off center...

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Chuck it up in a drill press - as long as the chuck isn't worn out or damaged, it will act like a poor man's lathe

[John McCorkle]

You know what...I think the stem roughness may be at least part of the problem if not the problem now that I think about it ....

Something else I noticed but thought little of until we are discussing it here are little brass shavings like hair thin showing up at the base of the press....I bet these are being shaved off the inside mouth of the sized brass by the tooling marks on the expander

Took a picture of the little brass hairs to show you what I mean...also here is a pic of the stem itself, you can see the tooling marks kind of...it is more a skill of angle and lighting I just don't possess to get this to come across on a picture

Can feel them with my fingernailhttps://uploads.tapatalk-cdn.com/20200306/c37dcc908cf6fc1e444a5a879010eb7b.jpghttps://uploads.tapatalk-cdn.com/20200306/9d6d8cbd53ce6d27de7a28f6c61c30e0.jpg

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[DonMountain]

I'm noticing several split cases in this operation (doing these on a single stage press at the time just to get a feel for it and glad I am...I can absolutely feel when they split) using Lee does with a 38sw powder through expander I polished up the mouth just a touch with 1000 grit followed by strop paste to really smooth/polish it up but didn't take any off the diameter of the expander stem when doing so.

A 38 S&W typically takes projectiles measuring 0.362", whereas a 9 mm Luger takes projectiles of 0.356". It looks to me like you have a combination of problems. Grossly over expanding the cases, and in the high-tension area during an expansion the leading edge of your oversized expander is pealing off the interior of your cases. Along with the rough machining of the LEE expander you are using. Buy a better quality expander of a more correct size for 9 mm Luger.

[John McCorkle]

A 38 S&W typically takes projectiles measuring 0.362", whereas a 9 mm Luger takes projectiles of 0.356". It looks to me like you have a combination of problems. Grossly over expanding the cases, and in the high-tension area during an expansion the leading edge of your oversized expander is pealing off the interior of your cases. Along with the rough machining of the LEE expander you are using. Buy a better quality expander of a more correct size for 9 mm Luger.I would agree with you if not for tons of guys here using this exact setup with none of the issues I am seeing... I wouldn't have thought to use the 38sw expander from Lee if not for others using it with great success, which is why I'm curious what could be causing it

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[John McCorkle]

So, put in some work on the expander stem with the 1000 grit paper and hit it good with my honing/stropping compound (product called tormek found at woodcraft for honing chisels - I use it to home straight razors)...stuff is great

Mirror polish on it now...and smoooooooooth like buttery glass. Hopefully this changes the tune a bithttps://uploads.tapatalk-cdn.com/20200306/78319a50f967c683f2f8acddf2427f94.jpg

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[Dusty Bannister]

The rough machining marks on the side of the plug would certainly try to grip the inside of the case as the case is withdrawn. That could explain the "tearing" you are finding on the case. Look really closely at a cut open case and see if you find some serious scoring. This is almost like shoving in a round file, tightly and then pulling it out and forming those wire shreds. I am surprised you have not pulled the rim of any cases, but perhaps the case failed before the rims tore. Might look to see if there are distorted rims too. It is possible that the final step was insufficient to polish the outside of the plug. Sort of worthless if it rips cases so a bit of polishing makes a very slightly reduced diameter? Not working out too well as it is.

[onelight]

The brass shavings come from working brass that has not been chamfered I get some because I don't chamfer 9mm brass . Your splits are probably coming from a combination of a rough oversized expander and brass that is brittle , a little lube might help but you may not need it along with polishing the expander even going over it with some 400 grit wet paper to nock off the sharp edges the drill press idea is the way I would do it . The brass probably needs to be annealed ( I would just pitch the ones that split )

[onelight]

So, put in some work on the expander stem with the 1000 grit paper and hit it good with my honing/stropping compound (product called tormek found at woodcraft for honing chisels - I use it to home straight razors)...stuff is great

Mirror polish on it now...and smoooooooooth like buttery glass. Hopefully this changes the tune a bithttps://uploads.tapatalk-cdn.com/20200306/78319a50f967c683f2f8acddf2427f94.jpg

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That is good stuff I use it for plane irons , wood chisels and stropping knives.

[Conditor22]

polish it up and let us know

[gpidaho]

I have good luck using the Noe expanders inside the Lee universal expander die. Not a powder through set up but you can pick the size you want to one one thousandth of an inch. Gp

[reddog81]

I've always hated the way the Lee powder through expanders grabbed the case and often times required a good yank to pull the case out. I have upgraded my 9mm to a Lyman M die and many other calibers to RCBS expanders. Hopefully that polish job does the trick for you.

Another trick I've found to making the whole process a little easier is to use a little Hornaday One Shot case lube on 9mm. Even when using a carbide sizer this makes the whole process smoother. I angle the spray downward so a little gets inside the case mouth to help make the expanding step a little bit easier.

[John McCorkle]

So did a second/third polish with 1000 grit and tormek and wow it's slicker than snail snot now...mic shows .3565 (reduction of 3 ten thou) which won't change much for the bullet swaging in the case

Tons of difference in feel now when expanding sized brass...so I'm going to crank out several and let you know how it goes if I see this issue again

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[Conditor22]

It helps to polish ALL your expanding and sizing dies NO MATTER who you get them from!!!!!

[JM7.7x58]

It helps to polish ALL your expanding and sizing dies NO MATTER who you get them from!!!!!

This is true. I bought two expanders from NOE, on the same day. One for my 30-06 and another for my 7.7x58mm. One is rougher than the other and becomes very "brassy" quickly. I use steel wool to clean this one on a regular basis. It would seem that each expander is unique.

JM

[DonMountain]

I would agree with you if not for tons of guys here using this exact setup with none of the issues I am seeing... I wouldn't have thought to use the 38sw expander from Lee if not for others using it with great success, which is why I'm curious what could be causing it

There are a lot of 9mm Luger pistols that have oversized chambers and will accept oversized projectiles, blowing out the cases to larger size to begin with. And maybe less expensive sizing dies that don't size the case down very far before running the oversized expander into them. So, less friction there on the withdrawal. And why are you trying to use a powder-through die on a single stage press? Why don't you try using the original die set with its own properly sized expander? Then when you change to a progressive press and try these other dies for some other cartridge you will notice the change if it isn't working properly. I use a three die set from a different manufacturer and have never seen the problems you are having. So, I would guess that you need to dispose of that odd, powder through die from a different cartridge that is not of the correct dimensions for 9mm Luger.

[John McCorkle]

There are a lot of 9mm Luger pistols that have oversized chambers and will accept oversized projectiles, blowing out the cases to larger size to begin with. And maybe less expensive sizing dies that don't size the case down very far before running the oversized expander into them. So, less friction there on the withdrawal. And why are you trying to use a powder-through die on a single stage press? Why don't you try using the original die set with its own properly sized expander? Then when you change to a progressive press and try these other dies for some other cartridge you will notice the change if it isn't working properly. I use a three die set from a different manufacturer and have never seen the problems you are having. So, I would guess that you need to dispose of that odd, powder through die from a different cartridge that is not of the correct dimensions for 9mm Luger.So alot of assumptions here I prob need to level set before I try to answer all the wrong questions...

1) it's not an expensive die set ...it's a Lee 4 die carbide 9mm set...you MAY be able to find cheaper dies but not by much and all that to say it's not a specific'match chamber' sizing die I'm using to size the brass in the first place

2) the powder through expander from Lee is a direct replacement that solves problems that some 9mm cast bullet users find...which is the stock expander in most die sets does not expand the case out enough to allow loading a cast bullet of relative alloys without swaging the boolit too small for the bore of your particular gun. Many see leading because they have undersized boolits flying down the barrel because though it was the correct size when loading, it gets swaged too small in the case itself.

The 38sw expander sizes larger and deeper in the case to allow that bullet to get in the case and stay the proper size so it's fired it is more accurate and leads less in the bore...it's not a mistake it's very intentional

3) I'm sure there are tons of things I could do differently but what I'm doing is no new trick...I found many here were having success and I thought I'd try it myself...not trying to fit a square peg in a round hole



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[Kraschenbirn]

When I first got my Kahr CW9, I saw quite a few of the same splits...mostly Federal and Speer brass...but polishing the expander of my Lee Pro-Disc seems to have taken care of the problem. On the other hand, I don't shoot that much 9mm and have (literally!) thousands of once-fired empties sitting on the shelf so, other than the PITA of salvaging primers, losing a few cases is no big deal.

Bill

[gwpercle]

I have good luck using the Noe expanders inside the Lee universal expander die. Not a powder through set up but you can pick the size you want to one one thousandth of an inch. Gp

I Agree 100% , Noe expanders plug + Lee Expander Die = a perfectly done job .
Powder through expander seems to be the problem...
Hope all your modifications make it work...
Gary

[toallmy]

That's a lot of brass shavings , something was definitely not right .
When I started using the lee S&W plug in my 9 mm lee powder through expander die it was sorta sticking when I lowered the shellplate occasional throwing powder out of the case so I chucked it in the drill press and polished it up a bit , it was even worse with squeaky clean brass - so I started lightly spraying my 9 brass with a homemade case lube
Before reloading them = silky smooth progressive reloading now . That 38 S&W plug in the lee 9mm die made my 9's cast friendly . Your getting it sorted out .

[Walks]

If you're loading on a Lee Progressive, then I don't see an answer to your problem other then a good polishing of the expander.

I've never had a problem like this. I do own a pair of Lee die sets. Gifted by a friend, a .38S&W & .44Russ. The .38S&W needed extensive polishing of the .365 expander "ball" and the inside of the bullet seating die. The .44Russ set, I just threw away the shellholder.
If We shot more then 200-300rds of each a year, I would buy a Quality Die set.

The Lee decap die does work OK.

You get what you pay for.

Sorry to be so negative. My experience with Lee has been very spotty.

[fredj338]

I use a MBF funnel in my Dillon, never seen a split case like that in 10s of 1000s loaded.

[Conditor22]

I had a member on CB fabricate some NOE type expander dies with a hole in them to fit in a lee powder through die. Saves having 2 dies on the press

[John McCorkle]

Mostly the powder through was an expedient way to go...I think I paid 6 bucks for 2 plugs and shipping (first one as with most of their spare parts was free) I have a Lee pro 1000 press so only working with 3 stations means I need to expand and drop powder together

Was testing the new expander on the single stage to see how it was when I ran into the issue...glad I did.

**Update**

Have run through several hundred cases now that it's all polished up with zero split cases. Will do prob a thousand more just to make sure bit looks like the polish has done the trick

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[gpidaho]

Glad to hear the problem is solved John. Gp

[John McCorkle]

Glad to hear the problem is solved John. GpThanks and thanks to everyone else here too....I can't tell you how much I enjoy this forum and it's members... awesome group of guys man

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[tazman]

Now I have another solution to a problem to add to my list.

[jimlj]

I may be wrong on this, but it seems I read to use the powder through expander from a 38 Super die set, not 38 S&W. I believe the 38 super expands further into the case than the 9mm expander does.

[onelight]

I may be wrong on this, but it seems I read to use the powder through expander from a 38 Super die set, not 38 S&W. I believe the 38 super expands further into the case than the 9mm expander does.
I would have thought the same thing and it might work but some of the guys here have had good success with the 38 S&W and know it is available so they recommend what worked for them.

[fcvan]

it was sorta sticking when I lowered the shellplate occasional throwing powder out of the case ... so I started lightly spraying my 9 brass with a homemade case lube
Before reloading them

I am not using the S&W expander and never polished the original 9mm expander. I did adjust to where a .358 sized boolit easily fit in the case mouth. The lead I was casting was originally from a ranger where swaged hollow base wad cutters were fired, very soft stuff. I did not experience boolits being swaged too small causing leading or poor accuracy in many 9mm firearms, pistol and carbine. Lucky? Nope. I did try sizing to .357 and they keyholed at 15 feet, not very lucky, in fact the opposite!

Your comment about lubing cases (secret recipe? :) ) got me thinking. Many years ago I changed my case cleaning regimen. Basically 1) cases are de-capped and rinsed in hot soapy water. I don't double rinse them with, often just strain. 2) cases are resized and rinsed in soapy water with lemon juice and let stand for about 5 minutes as it really takes care of the oxidized zinc in the brass. 3) brass is strained and goes wet into the tumbler with ground walnut. The moisture from the brass dampens the walnut enough to cause it to swell and scrub better. 4) my ground walnut in the tumbler gets a table spoon of Turtle Zip Wash every once in a while. TZW has a slight amount of wax in with the soap and so while polishing and as the walnut dries, it leaves a slight coat of the wax. The walnut media is generally dry withing the hour, and the brass shines like new.

The slight wax coating seals the pores of the brass so that finished cartridges stay shiny like new longer than factory boxed cartridges. The brass is not so slippery that it caused concerns about the brass not adhering enough to the chamber walls during firing. My 9mm AR 15s are blow-back and that would be a concern.

Until I read your comment about 'case lube' I totally forgot about how the brass stuck less during the down stroke of expansion/charging of the case. The reduction of force was noticeable enough, but I had forgotten that due to many years and many 10s of thousands of rounds loaded since I started the TZW clean/polish routine.

As an added plus, I haven't bought new walnut media in 10 years. I have enough to fill the tumbler twice and 2 zippered burlap bags for washing the walnut. The walnut is getting a lot of soap residue between the soapy water and the TZW that I can put the burlap bag under running water until the water runs clean and the set in the sun to dry which takes 4 to 5 hours, less if I just put it back in the tumbler and run it. The walnut is stained black from the zinc oxide but coarse feeling as if new. All good in my book, even though new ground walnut is quite cheap from the pet store as lizard bedding.

But, I forgot about the 'lube action' of the TZW until I read your comment.

[Burnt Fingers]

1. I, and many others, always use Hornady One Shot on straight wall pistol brass AND 9mm. It makes life a LOT easier. The difference is amazing.

2. Those brass hairs....I can load 1000 rounds at a setting on my Dillon and not see any, and I don't, and never have, chamfered any 9mm brass. I've got 10 gallons of the stuff and I just scoop it out of the bucket, hit it with the One Shot, let it dry for a couple of minutes and drop it in the collator.

3. I'm using a custom powder funnel on my Dillon. The factory funnel is great for jacketed bullets. It sucks for .357-.358 cast bullets.

[onelight]

The main place I see them is when using the Lee expanders they are rough , chamfering will stop it with them and it is worst with the first loading , polishing the expander will also stop it. I use ArmourAll ultra shine (a recommendation from here) in my last rinse when cleaning brass and the wax is all the lube mine seem to need with carbide dies makes a noticeable difference .

[JeffG]

I would agree with you if not for tons of guys here using this exact setup with none of the issues I am seeing... I wouldn't have thought to use the 38sw expander from Lee if not for others using it with great success, which is why I'm curious what could be causing it

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I agree with DonMountain on this. I believe most people using a non standard oversize expander for 9mm are using 38 Special expander because it is only .001 - .002 bigger in diameter and goes deeper, to help stop sizing down the base. 38 S&W is in the .361 .362 range, which is a big jump. I’m shooting at least 6 different brands of 9mm guns, with .357 cast in all. Using a standard 9mm Lyman M die allows the bullet to just sit inside the neck without any trouble while loading.

[jimlj]

I would have thought the same thing and it might work but some of the guys here have had good success with the 38 S&W and know it is available so they recommend what worked for them.

I just read several old threads. Turns out the one I thought said to use a 38 Super expander was using 38 S&W like the OP, my bad.

[Conditor22]

FYI Many European 9MM's run several thou bigger than the American 9MM.

Always slug your barrel or do a chamber cast before buying a sizing die.

[RydForLyf]

Is there a drop-in replacement expander for the Dillon 9mm? So many have been mentioned, I’m not sure which would fit.

[Burnt Fingers]

Is there a drop-in replacement expander for the Dillon 9mm? So many have been mentioned, I’m not sure which would fit.

LatheSmith makes them, I've never used one of his but they are supposed to be great. I got mine from Uniquetek.