9 mm Sizing Question

[whisler]

I am just beginning to reload for a new-to-me 9 mm pistol. I have been reloading, both J-word and cast, for 38/357, 45 and 380, but only recently the 9 mm, which I have read can be troublesome.

My question involves sizing, but the case not the boolit. My barrel slugs at 0.3550 (with a micrometer) and my Lee 358-125 RF boolit slugs @ 0.3575, so 0.0025 oversize which should be great. As seems to be common, when the boolit is seated and then pulled the base has been swaged down. The boolit was seated to 1.085 OAL (just short of the crimp groove) and then pulled. The base now mics 0.3563.

Question #1. How are my odds that 0.0013 over groove diameter will avoid leading. Alloy is 97% Pb, 1.5% Sb, 1.5% Sn and water dropped from the mold.

Question #2. My Lee powder-thru expander mics @ 0.3541 and an RCBS mics even smaller at 0.3532. If I order an NOE expander plug, what size should I get?

From what can gather from the NOE website and my measurements I think the .359 x .355 would be correct but thought I would check here first. I hate to waste money or time ordering the wrong thing.

[jsizemore]

What happens when you shoot it?

[fredj338]

Hard to accurately measure bore dia with calipers, so hard to say if you will get leading, but if the measurement is true, then you should be fine. I shoot a decently hard alloy in 9mm, about 12bhn, even for 9mm minor. I generally powder or HT coat these days & have no issues. I size everything to 0.357" for several diff pistols.

[whisler]

Jsizemore: Haven't shot it yet. Hearing how troublesome 9 mm can be with cast boolits, I thought I would seek out a little advice before possibly needing to de-lead the gun.

Fredj338: Groove dimension was measured by slugging and using a micrometer, so it should be real close. Alloy should be in the 10 - 11 range, as I don't think I have enough Sb to harden much from the water drop. It was just more for convenience.

If I need to open the case more, do you think the .359 x .355 expander would be the appropriate choice?

[Bzcraig]

Shoot it then report back if you have any issues.

[reddog81]

I'd try out what you've got. You don't want to expand the case mouth too much and loose all your neck tension. Even worse than an undersized bullet is a bullet that sets back in the case.

[jsizemore]

I'd shoot it to see if you do have a problem. No need to chase windmills.

If you do have issues, Chore Boy is your buddy.

[whisler]

O.K. I'll give it a try. I have plenty of Chore Boy.

[lotech]

There may be a rare exception, but shoot the largest bullet that will chamber without difficulty. This may be .357, .358, or .359. WW alloy is fine for most loads, but experimentation may be worth the effort.

[Moonie]

The first step I would suggest is using the Lee 38 S&W powder through expander in that 9mm expander die. It will expand further into the case and help with the issue of the case sizing down the cast boolits. I have one but I also have one of the early NOE PTE's that works perfectly, I believe he stopped offering these.

[whisler]

First I'll try what I have. If that doesn't work, I'll cast some more and see what they mic at unsized. I already sized all I cast @ .3578 as I also use them in 38/357 and that size seems to work fine in those calibers.
If needed I'll pick up a 38 S&W PTE die.
Thanks for the replies and I'll report back when I have anything further.

[whisler]

Reporting back: It seems that 0.0013 over groove diameter with my alloy and Ben's Liquid Lube (BLL) is not enough to prevent leading in my CZ. Shot a load of 4.2 gr. of 231 and it leaded in 10 rounds, not severely but end to end. Shot 10 rounds of a load of 4.5 gr. of 231 and leading got worse. Cleaned it all up with Copper scrubber strands and Kroil.
I am going to try several things, one at a time. I will order a Lee 38 S & W expander plug. While I am waiting I will re-lube current boolits with a lubri-sizer and different lube and try those with the same load. If that fails I'll try a harder alloy and re-shoot.
I have plenty of copper scrubber strands. LOL

If those fail, the S & W expander should be here by then.

[Cherokee]

I use a Lyman 38 super expander button for my 9mm to go deeper into the case and open the mouth enough for seating. 38 S&W should do the same thing, I just used what I had.

[whisler]

Well, I decided to pull down the remaining rounds from my first test. As I was dusting the 231 powder off of the boolits so I could recycle them, I decided to measure the base once again. To my great surprise they consistently measured 0.353. No wonder they leaded.
Either I read the mic wrong when I did my initial measurements or I accidentally caught the edge of the upper band in my measurement. Either way they were doomed to failure. I have serious doubts that even a harder alloy will resist that much swaging.
My 38 S &W expander plug is due to arrive Saturday, so I'll just wait until then to proceed.
User error strikes again!!!

[toallmy]

That 38 s/w expander and a 50/50 blend made everything work out for me .

[trapper9260]

I have one 9mm that I use some of the dies I have to load my 357mag with and works for it.I know I should try it also in my other 9mm but for when I slug them the slug is where the 9mm should be.That one I use the 357mag dies on is over size of the 9mm for cast.

[whisler]

Reporting back: 38 S & W expander button fixed my swaging problem but not the leading problem. Changing from BLL to Speed Green lube was also a no go. So I mixed up a harder alloy (13 BHN). WW 231 @ 4.5 gr. still showed leading in 12 rounds with Speed Green lube.
So I switched powders to Unique @ 4.7 gr. No leading after 23 rounds (all I loaded for the test). Unique also seemed to group better but that may have just been coincidence.
Guess I will load up 50 rounds with Unique and see if it still looks good. Wish me luck!!!

ETA: The 125 RF feeds fine in my CZ. Looks like Doug guy did a good job of throating the barrel.

[marek313]

Couple things that come to mind:

1. 9mm lead more so then lets say 45acp so harder alloy might be necessary
2. I'm not sure when you cast those but I usually let my boolits sit for at least a week to allow it to fully harden. That helps with minimal swaging when seating.
3. You might want to try powder coating those bad boys. I know it helped many people with their problematic 9s. While conventional lubes work for many in 9mm powder coating is better in my opinion so if your having problems PC might be your answer.
4. 38S&W expander but you already got that covered.

I shoot 4.2gr of HP39/W231 under Lee 125gr (sized to .3575 because thats what my p320 likes) without leading all the time. I also shot it with unique, titegroup, HS6 etc and I never had any leading with any of my powders.
I do take my time when I powder coat so my boolits have a nice thick coat. I call it TPJ as in Total Polymer Jacket

[whisler]

I water dropped my lead and waited 2 weeks to get to 13 BHN. If higher round count with Unique still doesn't lead I am good to go as I have quite a bit of Unique. If not, then I can try an even harder alloy or give powder coat a try.
Thanks for the suggestion.

[fredj338]

Reporting back: It seems that 0.0013 over groove diameter with my alloy and Ben's Liquid Lube (BLL) is not enough to prevent leading in my CZ. Shot a load of 4.2 gr. of 231 and it leaded in 10 rounds, not severely but end to end. Shot 10 rounds of a load of 4.5 gr. of 231 and leading got worse. Cleaned it all up with Copper scrubber strands and Kroil.
I am going to try several things, one at a time. I will order a Lee 38 S & W expander plug. While I am waiting I will re-lube current boolits with a lubri-sizer and different lube and try those with the same load. If that fails I'll try a harder alloy and re-shoot.
I have plenty of copper scrubber strands. LOL

If those fail, the S & W expander should be here by then.

That sounds like a lube/alloy failure.
I generally start a test with Unique & a new lead bullet. If it won't shoot, another powder probably wont either.