Solutions to boolits being sized down after loading

[jason867]

I've been doing a lot of searching and research, but I haven't found any satisfactory answers, or if I did I didn't realize it because of information overload.

Anyways, I'm reloading 9mm luger cast and my boolits, which are big enough before loading, are getting sized down during the loading process.

I will try to be as detailed as possible here:

My 9mm gun's barrel slugs out to .355". It's a polygonal barrel, by the way.
Using Lee's 9mm luger 356-125-2R round nose in a 6 cavity.
Pure clip on wheel weights, nothing added, air cooled. Tested 12bhn with Lee tester.
Bullets as cast are anywhere from .357" to .360", usually slightly oblong.
I do not size my bullets, from what I understand they are plenty big enough for my barrel.
So far I've only used Lee liquid alox lube, as soon as weather permits I will be trying Rooster jacket lube as well.

Loading these up on a loadmaster with lee's 4 carbide die set.

At first, my pulled bullets were coming out at .355" or .354". I figured out that the carbide ring in the FCD die wasn't helping, so I knocked it out so that it's only a normal taper crimp die.

Then, I found out that my brass was sizing my bullets down as well. I found that I could raise my sizing/depriming die up some so that it only sizes about half of the case. Now my pulled bullets measure .356" & .357", and they still chamber, although they don't fall out cleanly, but I don't struggle to pull them out of the chamber, so I figure they will fire and cycle fine.

This may be big enough, but I haven't been able to test that yet.

What are my options to further reduce the undersizeing that is still going on in my reloading process?

I know I could try water dropping my bullets (which gets me about 21bhn). But I'm not sure that would help with my accuracy.

What are my options as far as expanding my cases a little bigger? I've heard of getting bigger bushings and using the Lyman 'M' dies.

Where can I get other bushing sizes and what size should I try?

Are the lyman m dies adjustable so that I can expand the cases just right? Or are they stuck to a set amount? I guess I don't understand what their advantage is regarding this problem.

Thanks in advance.

[edit] I thought I should add that I'm only wanting 25 yard paper plate accuracy with minimal or no leading and easy cleanup.

[liljohnnie]

Hi Jason.I'm not exactly sure of what the perceived problem is.Are you having leading problems,accuracy problems or both?
If your pulled boolits mic @ .356 & .357 and your barrel slugs @ .355, it would sound to me like you have solved your own problem.
Remember the proof will show up on your target when you are able to test your loads.Should you still experience leading or accuracy issues then i would suspect your primer or powder charge and make adjustments there.
But if your gun happens to be a Glock (since you mention a polygonal barrel) then the only advice i can give is to not shoot unjacketed boolits through it. Perhaps there is another member here that can give a more informed response on lead boolits shot through a Glock since i do not own one.

[jason867]

My gun is actually a Bersa Thunder 9mm.

I know glock recommends not shooting lead through their barrels. But from what I've read, seen, and experienced, its not something to worry about.

As I haven't tested this load yet, I don't know how it will work out.

I just want to know what else I can do in the event that accuracy and leading can't be improved with adjustments to the powder and primer.

[Doc Highwall]

Your expander plug is too small, also softer alloy will deform easier.

[jason867]

Your expander plug is too small, also softer alloy will deform easier.

I understand that, but how do I get a bigger one?

[BeeMan]

Jason,

You are not alone on this. In my case I got the necessary accuracy fairly easily but leading after even 30 rounds was significant. This was true despite trying different powders and different charge weights for each.

The standard sizing die was taking the case down to .348 at the bottom of the seated bullet. Boolits went in at .3575 and after pulling they were about .353, well undersize for the .355 bore.

I ended up making an M-type expander to allow for .354 to the depth of the seated boolit. Pulled slugs are now at .357 so bore fit is fine.

This still did not eliminate all leading so water dropped was the next attempt. The harder boolits at the right fit got of most of the leading, except for about the first .75 inch in front of the chamber.

Next up is trying lube changes.

If you have to pursue more than just size, please post your results. Sometimes the gun insists that more than just fit and powder type / charge needs tweaking.

BeeMan

[Roundnoser]

If I'm reloading 9mm with a .357" diameter bullet, how much do I expand the case body to prevent the bullet from pinching at the heel? I read somewhere on this forum that the cases should be opened up .001" smaller than the bullet diameter. Does that sound right?

[jason867]

something along those lines.

[ANeat]

Could you use an expander out of a 38 special die? Or just use a 38 special die if you could adjust it enough to do a 9mm case. or perhaps some other die where the bullet is a little larger

[jason867]

The expander for a 38 is too short for use with 9mm.

I didn't want to screw up my 38 adjustment so I didn't bother trying. I might try it if I don't find a better solution and I need more girth than I got now.

what about these lyman m dies, does anyone know if they work better for 9mm cast?

[buyobuyo]

Lee dies do not expand the case. They only flare the mouth of the case.

The Lyman M-dies both expand the inner diameter of the case and flare the mouth. The dies consist of 3 parts (the body, stem, and expander plug). There are two different body lengths and two different stem lengths depending on which die you buy. For 9mm and .38/.357, the only difference is the expander plug, so you could buy one die and then get the other expander from Lyman to switch back and forth.

The 9mm expander measures .353 at the expansion section and .357 at the flair section. The .38/.357 expander measures .356 at the expansion section and .360 at the flair section.

I've loaded .358 sized ACWW boolits in 9mm without any case swaging using the .38/.357 M-die. The .38/.357 expander will expand the 9mm case almost the entire length, so you will need to put the carbide ring back into your FCD to get the rounds to chamber. The 9mm expander doesn't expand the case as far down so you may be able to run without the carbide ring in your FCD.

[jason867]

Say I got the 38/357 m die and it worked keeping my 358 boolits at 358. Wouldn't running them through the FCD with the carbide ring squeeze the bullets back down to 355?

Or should I get a 38/357 FCD die for that?

[BeeMan]

Jason,

To avoid excessive working of the brass and sort this out try these steps:

1. size and decap w/ 9mm die
2. expand w/ 9mm expander, belling the case mouth enough to allow starting the boolit base into the case
3. expand a second time w/ 38 expander, just enough to open the ID to where the bottom of the seated boolit will be
4. prime and charge case
5. seat boolit in 9mm die, adjusted to turn the bell back in.

It is a few extra steps, but provided your die dimensions allow for this you can load enough rounds to see if fit by itself will solve the problem. It worked for me with a combination of Hornady 9mm dies and an old RCBS 38 expander. No need for a FCD, or even a separate taper crimp die.

Then spend the minimal money for an m type die. Buckshot on this board may be able to help if you need a custom m die expander. Mine was fabricated in the tool room at work after hours.

BeeMan

[Calamity Jake]

Say I got the 38/357 m die and it worked keeping my 358 boolits at 358. Wouldn't running them through the FCD with the carbide ring squeeze the bullets back down to 355?

Or should I get a 38/357 FCD die for that?

Forget the FCD and get a taper crimp die for the 9mm

[462]

Try an M die and a conventional taper crimp die.

[jason867]

having knocked the carbide ring out of the lee fcd, this makes it a conventional taper crimp die, no?

[buyobuyo]

Say I got the 38/357 m die and it worked keeping my 358 boolits at 358. Wouldn't running them through the FCD with the carbide ring squeeze the bullets back down to 355?

Or should I get a 38/357 FCD die for that?


My FCD doesn't swage down my .358 boolits.

9mm is a tapered case, so the carbide ring of the FCD should only be working on the lower portion of the case, which is below the bullet base. Some people say their FCD swages the boolit, but I haven't experienced it.

Maybe, I'm just lucky... :?:

[jbelder]

Your expander plug is too small, also softer alloy will deform easier.

+1 on that! The expander spuds on most dies are made for jacketed bullets! Get buckshot to make you a bigger expander spud.

[1hole]

What are my options as far as expanding my cases a little bigger? I've heard of getting bigger bushings and using the Lyman 'M' dies."

I don't know what "bushing" you refer to but no expander can be adjusted for diameter. The M die expander plug is the normal diameter for the caliber. It adds a short section (about 1/16") of diameter a couple thou larger than the bullet immediately before the flare section to prevent cutting the bullet heels during seating. The M expander is an excellant design but most people just do enough flaring to work almost as well.

You are worrying about what I believe is a non-issue. Hard cast, slow speed, low pressure bullets do need to be at, or even a tad larger, than groove diameter. However, the acceleration of cast bullets in high pressure loads WILL cause them to obturate (fill the bore) if they are even close to the proper diameter.

Your die is no longer an FCD, it's simply a taper crimper.

[Wayne Smith]

If you genuinely want a larger expander plug for your Lee 9mm dies contact Lee and they will make you one. Tell them the diameter you want. Conversely, contact Buckshot on the board here and he can make you one, too.

[jason867]

I did contact lee, and they sent me, for free, an expander plug made for 38S&W. It's a little wider (the width I figured I'd need actually) and goes in a little deeper as well.

I tried it out and after pulling a boolit from a finished cartridge (air cooled wheel weights, measures 12bhn) I could measure only a negligible difference in diameter, it didn't appear to have been squashed down hardly any. If I remember correctly (it's been a few weeks) it started out .358" to .359" and aftewards measured like .3575" to .358" or so. I figure I only really need .357"

I have not been able to test fire any yet, but I'm hopeful that I will see a marked improvement.

I anticipate that I will have the same problem for .40S&W, but I don't think lee produces a standard expander plug that will be big enough for this. I may have to go custom as you mention.

[PacMan]

If you have an old 38/357 expanding die or can get one you can pull the plug from the die and grind the end down just slightly longer than bullet depth (leaves a little extra length to round off the end)If the dia.is to large chuck up the plug in a drill press and using 200-300 grit cloth to reduce the size.I also changed the taper on the belling part of the expander to fit my needs better.