9mm Neck Tension Issues (random)

[lordpaxman]

Tagging in as interested in the answer. I run mixed HS as well and the majority is FC, Blazer, REM and Win.

This is when I measured the bullets to ensure they weren’t undersize. My second thought was that the 3 cases didn’t size properly or had not been sized. I pulled the bullets, and ran the cases through the sizing die with decapping pin removed. Inside case diameter was 3 thousandths under bullet diameter of .355, or actually .352 This is correct and has worked properly for 1500+ previous rounds.

I find it hard to believe your sizer die is going fail. Did you measure the actual bullets that had dropped in the case, or just bullets in the overall batch? After you took the step to re-run these cases through the sizer again, did you see if you attempted to seat the bullet without expanding, would you have enough neck tension?
Same thing after the expanding step? That might help narrow down if there’s an issue in either one of those steps.
I’ve resisted a Mr. Bullet feeder, so I don’t know the mechanism, but is there any chance the bullets can get seated further down than the step provided by the M die?
Questions only I have at the moment. Good luck.

 

[Alex G]

Suggest trying another brand of sizing die.

If you’ve got another brand handy, plug ‘em in for awhile and see what happens.

I don’t have another one one hand, but I can look at picking one up. What would you all recommend? If it’s a good die, I can fork out the $, so cost isn’t the biggest concern.

BTW, you can still read the headstamps clearly. Doubt you’re problems brassy.

Then why is it primarily the FC and Blazer headstamps? Just curious. Dimensionally they seem the same as the S&B, which is probably one of the best headstamps for 9mm I’ve come across.

 

[Blue68f100]

Softer brass will have less spring back than hard brass. Have you measured the ID of the brass after sizing? Then measure again after expanding. I know that Rem use to run thin and soft and would cause issues years ago. I sorted all of my Rem out and gave them to someone needing brass. On the ones that are soft/easily sizes, try seating a bullet without expanding and see if you get neck tension. If so you may want to reduce your expander, or not expand at all on those pieces of brass.

 

[rfwobbly]

Well... Either the Expander is expanding the case too much or the bullets are too small.

Lots of guessing and mis-information here.

WeekendReloader had it correct. The Sizing Die should take the exterior of the case to an under-size condition. Far enough under-size to make up for ANY variation in case wall thickness. THEN, the Expander follows that and brings the inside of the case mouth out to a dimension that will provide proper bullet grip... provided that the bullets are the proper diameter.

The diameter of the Expander is typically 0.002 to 0.003" smaller than the diameter of the bullet. Your Expander can be the wrong diameter, or your Expander can be set to enter too deep. That's where you want to place your primary focus when looking for bullet holding issues.

You could also be inserting the bullet too shallow. 9x19Luger typically likes the bullet seated at least 0.200". You should not be trying to get the ogive close the lands. Seating depth is much more important in pistol.

Hope this helps.

 

[jmorris]

Do the bullets have neck tension after seating before crimp?

If no, see if you can manage to seat one before you expand. If the die doesn’t size enough you will be able to as there won’t be enough neck tension right from the start.

If you can’t because the case is sufficiently “under after sizing, you are over expanding.

If yes, you are putting so much crimp on the case you are swaging the bullet down and lead can’t spring back like the case will, so the neck tension you had after seating is gone because of the reduced diameter of the bullet. Pull one and you’ll see the ring. At that point, applying more and more crimp, doesn’t make things any better.

 

[NMexJim]

I don’t have another one one hand, but I can look at picking one up. What would you all recommend? If it’s a good die, I can fork out the $, so cost isn’t the biggest concern.

Then why is it primarily the FC and Blazer headstamps? Just curious. Dimensionally they seem the same as the S&B, which is probably one of the best headstamps for 9mm I’ve come across.

What I meant was that the wear from numerous firings begins to blur the headstamps. By the time you get up in rounds, the lettering will begin to be hard to read because of battering and sliding. The statement was said a bit tongue-in-cheek, but there's some truth there as well. I would warrant that brass is low in number of loadings - 3x maybe. It's one of those old-timer statements. But, primer pockets looseness is a truth. I've run FC and Blazer and SB all together for junk ammo and never noticed one going south faster than one of the others. But, for serious work, I do seek out Win cases and use those in lots of 1,000. I run a bag until I get 5X and then those start being used for light loads.

I personally find it hard to imagine that you've fired those cases enough for them to be hard enough to not size or not to hold sizing. I've never seen it, but then I don't run blazing-saddle loads either.

There is a lot of fact in the thread about engraved bullets shown above. Too much crimp can be a problem. But, you're talking about a case not sizing, so go up to rfwobbly and re-read what he says. See if you can sweet-talk him into PM'ing you a couple of articles.

If you've run out of options like having another sizer, then call Mighty Armory. They don't want bad product out there and people taking their names in vain.

Good luck.

 

[vaalpens]

No. Also see my comment that I adjusted the M-Die to flare just enough that the bullet will sit without tipping over. No disrespect, but it doesn’t seem like you read the original post very thoroughly.

So the issue is not the expanding step.

Seater die-Lee (set to seat and crimp in one step. Yes, my crimp is correct, I’ve pulled bullets to check)

How do you know the crimp is correct. It looks correct when you pull the bullet, but the bullet comes out easily and can be pushed into the case.

My suggestion would be to seat without crimping, then check to see if it is still easy to push or pull the bullet. If it is, then it must be the seating process or the bullet. If not, then it is the crimping process.

 

[Alex G]

I find it hard to believe your sizer die is going fail. Did you measure the actual bullets that had dropped in the case, or just bullets in the overall batch?

Yes to both. Bullets are consistently .3555-.3560

After you took the step to re-run these cases through the sizer again, did you see if you attempted to seat the bullet without expanding, would you have enough neck tension?

It would be impossible to get the bullet into the case (non-tapered bullet heel) so I had to flare

any chance the bullets can get seated further down than the step provided by the M die?

Not likely, the m-die has a profile which extends down in the case a certain depth. The mr. bulletfeeder simply drops the bullet on top

Do the bullets have neck tension after seating before crimp?

Seeing as how I do them in one step, and the crimp is just to remove any case mouth flare and nothing more, I’d imagine so but am not sure.

would the option of a case mouth flare die work instead of a full expander, or...?

 

[jmorris]

Seeing as how I do them in one step, and the crimp is just to remove any case mouth flare and nothing more, I’d imagine so but am not sure.

One could test this even seating/crimping at the same station, with the same die but it’s going to turn your process into a single stage one for the test group. You would need a shim to put between the shell plate and bottom of the die, so you can’t complete the stroke by a certain amount. The same amount, say .080”, and see if they all have good neck tension.



If they don’t, no need to go any further because the problem is not the crimp.

However, if they are all good at this point and you take that same sample group and now complete the last .080” of stroke in the die, completing the crimp and now they have insufficient neck tension, you know exactly where the problem is.

would the option of a case mouth flare die work instead of a full expander, or...?

If your neck tension issue is not crimp induced, the first thing I would try after that would be to swap out the Lyman M expander for a regular one.

 

[Alex G]

One could test this even seating/crimping at the same station, with the same die but it’s going to turn your process into a single stage one for the test group. You would need a shim to put between the shell plate and bottom of the die, so you can’t complete the stroke by a certain amount. The same amount, say .080”, and see if they all have good neck tension.

View attachment 987531

If they don’t, no need to go any further because the problem is not the crimp.

However, if they are all good at this point and you take that same sample group and now complete the last .080” of stroke in the die, completing the crimp and now they have insufficient neck tension, you know exactly where the problem is.



If your neck tension issue is not crimp induced, the first thing I would try after that would be to swap out the Lyman M expander for a regular one.

good info! Thanks! I may have to look into getting a regular mouth flaring die

 

[GeoDudeFlorida]

good info! Thanks! I may have to look into getting a regular mouth flaring die

How did you check for cracked necks? Try a ping test - drop them from hand height or closer on a hard surface and listen to the sound. A cracked case will have a dull ping versus a solid case which will ring. I know you said you've already checked but I've had cracked cases with very small fissures I couldn't see or feel and they had exactly this issue - failed neck tension.

 

[243winxb]

I noticed on the cases that fail, that the case passes easily on the expander with very little effort most of the time

Replace the sizing die? Lee "Undersize" sizing die. This die is said to size .003" smaller. The "soft " plated bullets may add to the bullet hold/neck tension problem?

My new RCBS 9mm Luger die set is doing a fine job.

 

[Alex G]

How did you check for cracked necks? Try a ping test - drop them from hand height or closer on a hard surface and listen to the sound. A cracked case will have a dull ping versus a solid case which will ring. I know you said you've already checked but I've had cracked cases with very small fissures I couldn't see or feel and they had exactly this issue - failed neck tension.

I checked...I’ve processed 15-20k pieces of brass in the past couple months and I know what split case necks sound like haha

 

[Alex G]

Replace the sizing die? Lee "Undersize" sizing die. This die is said to size .003" smaller. The "soft " plated bullets may add to the bullet hold/neck tension problem?

My new RCBS 9mm Luger die set is doing a fine job.

yes, but at what cost? The bullet sizes the case back out anyway, and creates the waisting issue. Also, if it’s the M-Die causing the issue, it won’t matter what sizing die I use.

 

[jmorris]

Also, if it’s the M-Die causing the issue, it won’t matter what sizing die I use.

This is why it’s important to use the process of elimination and isolate the cause of the problem.

The good news is we are only talking about 3 dies (size, expand, seat/crimp) and two components (brass and bullet) so it shouldn’t take long to narrow it down.

 

[243winxb]

It would be easy to over expand the case with this RCBS expander. If the M part goes in to deep, then it starts flaring the case mouth more. The case length may also be an issure, if die was set on tne shortest of brass.

 

[GeoDudeFlorida]

I checked...I’ve processed 15-20k pieces of brass in the past couple months and I know what split case necks sound like haha

Didn’t know you had figured it out. Sorry for interrupting.

 

[NMexJim]

Didn’t know you had figured it out. Sorry for interrupting.

Shucks, I’m bringing up the rear again! All the reloading I’ve done in near 50-years and I’ve never heard a case crack! Missed out again! You guys get all the fun.

 

[jmorris]

Shucks, I’m bringing up the rear again! All the reloading I’ve done in near 50-years and I’ve never heard a case crack! Missed out again! You guys get all the fun.

When I was young I could hear the high frequency hum of a tube TV that was on but without an incoming signal, these days I don’t always hear what my wife says. So it’s not always bad not to hear everything.

 

[243winxb]

I did a search, found this-

9mm - The carbide inserts in my RCBS and Lee dies are tapered. They are .391 at the base and .370 farther up in the die. They both work equally well and produce a tapered case.

My new RCBS CARBIDE 9mm Luger sizing die seems to have the tape built into the die? After taking measurement of my sized brass vs fired. Old ones just have a ring in 357 & 44.
Ma ybe all 9mm have the taper now??

 

[NMexJim]

Below should be the sizing die OP talks about. And, below is the stem set/decapper that you buy separately for the sizing die. It all looks pretty simple. Then, he's using the Lyman M-series expander which .243 shows above. That should be straight forward too. He does size on a separate press, but that shouldn't be an issue as long as the cases are sized and expanded correctly.

Then, he switches over to an LNL AP press, a case feeder (I assume Hornady) which shouldn't cause problems, and then a LNL powder drop, and we've covered how he sets that up. But, we haven't looked at the case feeder much but I don't think that should cause any problems.

Then, he uses a Mr. Bullet Feeder die and a Lee to seat and crimp in one step and he tells us that his crimp is correct. We haven't looked at Mr. Bullet much but that should just be collets used to drop bullets and have nothing to do with a case.

So, really, two steps. First Step, size and expand. If the brass is coming out of this stage correctly, then the problem must be downstream. Let's assume that they are. Ergo, the problem has to be in the next step.

Then, the Second Step - the case feed, the powder drop, the bullet feed (is this set correctly? You might be forcing bullets into the case somehow.), the Lyman seating/crimp. The Problem now has to be here somewhere if not actually in First Step.

Looks like an either/or situation. First step ok, then gotta be the second part.

Or, indeed the brass is not resizing. But, that should show up after First Step, right?

Over and out.

 

[Alex G]

We haven't looked at Mr. Bullet much but that should just be collets used to drop bullets and have nothing to do with a case.

the bullet feed (is this set correctly? You might be forcing bullets into the case somehow.)

Yep, bullet feed is set perfectly. For those not familiar with the Mr. Bulletfeeder die’s function, it’s two sleeves, one of which is the die body itself, the other is the dropper. The case pushes up on the internal sleeve, which allows the 3 ball bearings to fall back in their detents, and allowing a bullet to feed. The system is simple and virtually foolproof, and feeds jacketed, plated, hi-tek/powder coated and even conventionally lubed cast lead bullets well. I will include pictures below for reference as well, and know 100% beyond all doubt that the bullet feeder is not the issue haha.

I’ve got a Lee basic case flaring die on the way to see if that helps, if perhaps the cases with weaker neck tension are being over-expanded with the M-Die perhaps. At $14 or so for the lee expander die, it’s a cheap fix to try.

 

[jmorris]

I would locate the problem without messing with the bullet dropper first. Then add on the other stuff. Why I always suggest using a press as manufactured first and after one is happy and comfortable, add on after market stuff.

The MBF droppers, for pistol bullets often have larger expanders but if you had been successfully loading already, you would know that change to bullet feed and associated parts brought about a problem.

 

[murf]

I pulled the bullets

all 15, or just the four that had bad tension?

and ran the cases through the sizing die with decapping pin removed.

all the cases, or just the four with the tension problem?

Inside case diameter was 3 thousandths

how did you measure that?

what is the case wall thickness of the problem cases? what is the variation in that thickness?

murf

 

[Alex G]

The MBF droppers, for pistol bullets often have larger expanders

Uhh...the MBF doesn’t use an expander...? The charges case simply pushes it up and allows a bullet to drop into the case mouth

all 15, or just the four that had bad tension?

All 15.

how did you measure that?
what is the case wall thickness of the problem cases? what is the variation in that thickness?

Calipers, and I will have to check and get back to you on that. At work at the moment and don’t have my numbers with me