Please help me diagnose my 9mm case problem

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Doindia

Doindia

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Hey all, I am new into reloading. I was always told the best way to learn how to reload is to reload with someone with experience. Apprentice so to speak. Unfortunately I have not been afforded that opportunity and I’m doing this off of instructions/manuals/YouTube. I have reloaded and shot about 20 rounds that all shot great. Seemingly accurate and without issue. My problem is hopefully easily depicted in the pictures below. My finished product has an uneven/taper/bow in the casing. I thought the problem started at the neck expansion but I’m not so sure anymore. I’m expanding the neck just enough so the bullet doesn’t tumble out, but even then it already looks like it has a lot of flare from where it started. So I took it back yet another process to the very beginning. It appears as soon as I deprime and resize my casing with the Lee 9mm die set the casing immediately has a visible and measure-able taper. At first I didn’t recognize it because it was so slight. I put the calipers on it and the top of the case measures 0.3725 and at the bottom of what I thought should be a straight case it measures 0.3885, so out of the gate I’m creating this taper with the resizing die. Additionally my inner neck where the bullet seats measures 0.3475. To be clear these are the measurements of a straight case 9mm after the resizing depriming die. Next I set up my neck expander to accept a bullet just enough to where it can sit in the mouth and not fall out. As soon as it comes out of the neck expander the case is starting to look pretty manipulated in the sense that it started as a straight case, I tapered in with the resizing die and now I’m expanding the neck back out. Once I seat and crimp the bullet I am left with the wavy type bulge at the top of the case, then what looks like a taper inward like an hour glass then back out at the bottom.



I am doing this on a lee 50th anniversary breech lock single stage press. I am using once fired brass that I have tumbled and polished in corn cob media. My bullets are .355 although i do not have a brand. I am using 4.4 grains of unique and a 115g bullet (although this happened to the 124 grain bullets as well. I am setting up my carbide dies exactly how the instructions as well as a few YouTube video showed me. I have used the lee lube that comes in the die set as well as no lube at all on a few and the end product is still the same.

Kind of at a loss here any guidance or direction would be greatly appreciated. I am going to try to follow up with pictures if I am able to.
 
Welcome to the THR!
The pictures would help a lot, but, just to clarify a few things: 9mm is a tapered case, it isn’t a straight wall. From what you describe, the resizing process sounds just fine. You want the mouth of the case less than the bullet diameter, this provides neck tension which prevents the bullet from moving once it’s seated. Setback is not desirable, especially in 9mm.
The expander step sounds correct as well, you want just enough bell, or flare, to allow a bullet to set on the case mouth. Lead or coated bullets require a bit more bell, jacketed or plated bullets can get by with less.
From what you describe, you’re seating and crimping in the same step. The taper crimp should only removes the bell, it doesn’t or shouldn’t be anything more than that. It may be your crimp die is set to short, and you are buckling the case a bit. You may want to re-adjust the seat/crimp die, or try seating and crimping in separate operations which a lot of us do. If you want to seat/crimp in one operation, most die setups back out the crimp die so it’s not crimping and establish the seat depth first. Then back out the seater plug so it’s not touching the bullet, and screw the seater die in till you just remove the bell from the case. See if it passes the plunk test. Lock it down. Then you re-adjust the seater plug till it’s touching the bullet. You should also check to see when you do this that the case lengths are approximately the same. I don’t trim 9mm but you don’t want to do setup with a short case and then have all the long cases buckle. Good luck!
 
Guys thanks so much for the quick replies here’s are some pics.

The last photo is a hand load sitting beside a factory S&b load.
 

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Doindia said:
My finished product has an uneven/taper/bow in the casing.
Click to expand...
Welcome to THR and the hobby of reloading that is passion for some of us.

As lordpaxman posted, unlike straight walled cases like 40S&W/45ACP, 9mm is a tapered case and finished round will have the "Coke" bottle effect.

Look at following SAAMI max dimension drawings showing the difference between straight and tapered cases - https://saami.org/wp-content/upload...FP-and-R-Approved-2015-12-14-Posting-Copy.pdf

Here is 40S&W drawing showing .423" case neck and .424" case rim, essentially straight case.

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And here is 9mm drawing showing .380" case neck that increases to .394" case rim taper. Keep in mind that these are SAAMI max dimensions so your resized brass and finished round will likely have smaller dimensions. And as brass work hardens from repeated resizing and expansion from firing, resized case length will get shorter, often shorter than .750" when SAAMI max lists .754".

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Doindia said:
top of the case measures 0.3725 and at the bottom ... measures 0.3885, so out of the gate I’m creating this taper with the resizing die ... Lee dies
Click to expand...
This is normal since 9mm is a tapered case. Some brand dies have straight carbide sizer ring for the 9mm resizing die but Lee resizing die has tapered carbide sizer ring that follows this taper when resizing brass.

Here is picture of 9mm brass resized with Lee resizing die that produced tapered resized cases

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And after seating the bullet, shows "Coke" bottle effect

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As to bulging of case neck around the bullet, this is normal as resizing the brass reduces the inside diameter of case neck to smaller than bullet diameter and bulging of brass shows good neck tension, which can vary depending on the diameter of bullet as 9mm bullets can range from .355" to .356" typically. Keep in mind that if bullet tilts during seating, you will see one-sided bulging of case neck, so be sure the bullet is set straight as it enters the seating/taper crimping die.
Doindia said:
my first loads which I disassembled and noticed a very tight pinch because my jacketed lead was heavily indented.
Click to expand...
As to taper crimping, since case mouth brass thickness averages around .011", I usually add .022" to the diameter of bullet for my taper crimp amount. So for .355" sized bullet, you want to end up with .377" at case mouth which essentially returns flare back flat on the bullet (And very slightly more for thicker walled cases) - https://www.thehighroad.org/index.p...nd-bullet-setback.830072/page-3#post-10712225

Here is close up picture of taper crimp showing sharp 90 degree case mouth for proper headspacing with chamber and even bulge around the bullet base showing straight seated bullet and good neck tension.

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@lordpaxman. I had no intention of doing both seating and crimping at the same time and I am happy to separate which sounds like the smart move. I initially just set the die up the way the instructions said (as well as some YouTube videos) essentially screwing it in until it kissed the ram then backed it out 2 full turns and from there adjusted the actual seat depth with the other screw.

also this step above is an upgrade from my first loads which I disassembled and noticed a very tight pinch because my jacketed lead was heavily indented. After getting it right to where that was not happening this is what I’m left with. Also the bullet seems to be what is creating the buldge more so than the flare. When I press this bullet it seems to have little of no flare but the wave You see in the case essentially looks like it’s being made by the base of the bullet and any more crimping would start cinching at the led again.. if that makes sense. It almost looks as if the resizing die tapers the case to such a degree that the bullet itself is what is causing the buldge. I hope this makes sense.
 
@LiveLife Wow you guys are awesome, can’t wait to read your post On my lunch break. Looks like tons of great info. I really appreciate you all taking the time to help me out!
 
You don’t have to have the hourglass if you don’t want it.

The 9mm is tapered, back the size die out and you won’t under size the body of the case so much it looks that way when you seat a bullet.

That said, lots of folks just crank the die down to the shell holder and go. They will run.
 
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Doindia said:
photo is a hand load sitting beside a factory S&b load.

I am using 4.4 grains of unique and a 115g bullet
Click to expand...
Here's Speer load data for TMJ which is a thick plated RN bullet that can be driven to jacketed load data velocities - https://reloading-data.speer-ammo.c...m_caliber_355-366_dia/9mm_Luger__115_rev1.pdf
  • 9mm 115 gr Speer TMJ Unique OAL 1.135" Start 5.6 gr (1166 fps) - Max 6.3 gr (1244 fps)

And here's Alliant load data for copper plated RN bullet (When load data lists only max charge, we often reduce by more than 10% for start charge) - https://www.alliantpowder.com/reloa...owderlist.aspx&type=1&powderid=3&cartridge=23
  • 9mm 115 gr CPRN Unique OAL 1.135 Max 6.0 gr (1217 fps)
10% reduction is 5.4 gr so you may want to use higher than 4.4 gr for your load development. And many use 5.0 gr of Unique with 115 gr FMJ/RN bullets.

Lyman #49 lists 4.4 gr as start charge for 115 gr JHP that is seated deeper using 1.090" OAL. Since you are using RN profile bullet with longer OAL, you want to reference load data for RN bullets. Try comparing 5.0 gr load with 4.4 gr and see which shoots more accurate.
  • 9mm 115 gr JHP (Hornady XTP) Unique OAL 1.090" Start 4.4 gr (996 fps) - Max 5.8 gr (1233 fps)

FYI, here is step-by-step guide you can reference for your load development and powder work up with shooting tips for accuracy testing - https://www.thehighroad.org/index.p...-and-discussions.778197/page-10#post-11419509
 
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Guys thanks so much for the input. In regard to the load data I have seen so much variation. Including the Aliant load data. My goal was to dip my toes in the water with safe baby steps and work my way up. With that said I appear to be significantly lower than a lot of postings I am seeing. For now this is just plinking ammo and I will hone it as I prepare to do more. For what it’s worth I am using the hornady handbook of reloading. The pics below are why I started around the 4.4 mark. Let me know if I’m missing something.
 

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Doindia said:
My goal was to dip my toes in the water with safe baby steps and work my way up.
Click to expand...
That's a good policy and we often post to start low/conservative as you can always go higher.

Doindia said:
I am using the hornady handbook of reloading ... why I started around the 4.4 mark.

Let me know if I’m missing something.
Click to expand...
9mm is a small internal volume case that is affected by small changes in reloading variables.

If you look at the Hornady COL/OAL used for 115 gr FMJ RN, it's showing 1.100" which is as short as I use for 115 gr FMJ/RN bullet as any shorter, the tapered case will start to decrease neck tension to where the bullet will simply fall into the case. :D

So for most 115 gr FMJ RN and plated RN bullets, many use more typical 1.130"-1.135" OAL (Which is typical OAL variance many reloaders experience). I use shorter 1.110"-1.115" OAL instead of 1.130"-1.135" when using lighter powder charges to improve powder burn efficiency for more consistent chamber pressure build to increase accuracy. BTW, it's likely why Atlanta Arms reduced their 115 gr FMJ OAL down from 1.130" to 1.100" for their Elite Match AMU ammunition as it is loaded to lighter minor power factor of 132 - https://www.thehighroad.org/index.p...something-tonight.874560/page-2#post-11632664

Looks like your OAL is longer around 1.140"-1.150" which would reduce chamber pressure compared to 1.100" Hornady listed so you want to use higher powder charges and consider using shorter OAL for greater neck tension as you are using below start charge of load data using longer OAL.

Using shorter 1.130"-1.135" OAL, I would work up 4.7 gr and 5.0 gr loads next and see how they shoot compared to your 4.4 gr load.
 
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looking good doindia. i would make a dummy round (no primer, no powder) and make sure it fits and cycles through your pistol. the dummy round is also used to set up your seating die the next time you reload (same seating depth).

luck,

murf
 
fxvr5 said:
Let me guess, you pulled that one out of thin air.

I can think of other reasons to change the OAL, like using a different bullet or seating them deeper to fit tight chambers.
Click to expand...
Absolutely.

It is likely that Atlanta Arms uses different sources for FMJ and could have switched bullet during the pandemic shortage (I believe they had to during the last great component shortage).

But in the comparison barrel vs max/working OAL thread, even for my Lone Wolf barrel with very short leade (Shortest leade I have seen in any 9mm barrel), for 115 gr FMJ/RN bullet, 1.100" OAL is not required to clear the rifling as most FMJ cleared the rifling at 1.160"-1.169" with the exception of Winchester/RMR at 1.130" and Zero at 1.125" OAL - https://www.thehighroad.org/index.p...col-for-reference.848462/page-2#post-11465109

I guess I could email Atlanta Arms and ask why they decreased the OAL for 115 gr FMJ Match AMU (1150 fps) from 1.130" to 1.100" when they kept the OAL to 1.125" for Classic 115 gr FMJ (1160 fps)/Select 115 gr FMJ (1110 fps) and 1.120" for Select 115 gr FMJ Steel Challenge (1070 fps) - https://atlantaarms.com/products/classic-match-9mm-115gr-fmj.html

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  • Berry's 115 gr RN: 1.169"
  • Berry's 115 gr HBRN-TP: 1.169"
  • HSM 115 gr RN: 1.165"
  • PowerBond 115 gr RN: 1.160"
  • RMR 115 gr FMJ: 1.130"
  • Speer 115 gr TMJ: 1.169"
  • Winchester 115 gr FMJ: 1.130"
  • Zero 115 gr FMJ: 1.125"
 
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LiveLife said:
Absolutely.

It is likely that Atlanta Arms uses different sources for FMJ and could have switched bullet during the pandemic shortage (I believe they had to during the last great component shortage).

I guess I could email Atlanta Arms and ask why they decreased the OAL for 115 gr FMJ Match AMU (1150 fps) from 1.130" to 1.100" when they kept the OAL to 1.125" for Classic 115 gr FMJ (1160 fps)/Select 115 gr FMJ (1110 fps) and 1.120" for Select 115 gr FMJ Steel Challenge (1070 fps) - https://atlantaarms.com/products/classic-match-9mm-115gr-fmj.html

  • Berry's 115 gr RN: 1.169"
  • Berry's 115 gr HBRN-TP: 1.169"
  • HSM 115 gr RN: 1.165"
  • PowerBond 115 gr RN: 1.160"
  • RMR 115 gr FMJ: 1.130"
  • Speer 115 gr TMJ: 1.169"
  • Winchester 115 gr FMJ: 1.130"
  • Zero 115 gr FMJ: 1.125"
Click to expand...

Their 115 FMJ steel challenge round uses a different bullet. It is plated and not FMJ, according to this article;

https://www.shootingtimes.com/editorial/how-accurate-is-9mm-luger-match-ammo/99175


I asked them why they changed the OAL and speed of their AMU round. They did it because they switched bullets. Here was their reply:

"In the ongoing effort to increase performance, we never stop developing and tweaking to see if there is any room for improvement.

1. We made a profile change to the projectile.
2. This increased allowances for OAL.
3. The new profile and OAL resulted in significantly increased accuracy when the velocity was adjusted.

Everything can be tweaked... We never stop experimenting.
That is it.

Hope this helps.

V/R"

You don't have to speculate any more.
 
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