Need a tighter 40 S&W Die. Lee U die is too tight. Any suggestions?

[atblis]

I have a bunch of 40 S&W brass to reload and much of it is R-P with rather thin case walls. Just thin enough that my Lee sizing doesn't get it tight enough to have sufficient bullet tension and I get set back. Verified this on the setback rounds with a tubing micrometer. Yep, they're thinner than everything else. No other brass does this to me (and not even all R-P cases).

 

So I got a Lee U die, but it's too tight IMO. I really just need 0.001" to 0.002" tighter than my current die. It's possible my die is on the large size tolerance-wise. But before I start rolling the dice on new dies, are there any manufacturers known for being a little on the tight side for their pistol dies?

[Nolan]

How is the undersize die too tight?  If it is just hard to operate the press, use case lube.  Any brand of case lube will work for pistol brass and will make the press sooo much easier to operate.  

 

What bullet are you loading?  Have you measured the diameter of a large sample of the bullets?

 

Nolan

[zzt]

I'd recommend the Lee Factory Carbide Crimp die. Seat and then crimp with this die.  It sizes the case on the way down and again on the way up.  Zero problems.  FWIW, I use a Hornady sizing die.

[atblis]

Regarding the Lee FCD, wouldn't I then effectively resizing the bullet too? 

 

When in doubt, start measuring (done with good calipers, not a mic so...)

 

Bullet that set back under finger pressure measures 0.400" (as do several others)

Wall thickness on offending R-P case measures ~0.011" (measured using tubing mic)

Wall Thickness on other headstamps meaures 0.012"+

Loaded round measures 0.421" OD (the case that setback easily)

Regular Lee die measures at 0.417"

U Die measures 0.413"

M die expander measures at 0.498"

Case sized in regular Lee die measures 0.420"  OD

 

I think it's R-P cases that are the problem. Doing a little more reading on the internet, there's a good bit of bitching about the R-P cases. It sounds like they get a little work hardened after a couple loadings and lose neck tension (being on the thin size contributes). I am surprised they spring back that much.

 

Hmm, don't want to sort my brass. ~Half are R-P cases.

 

 

 

 

 

 

 

 

 

[AHI]

Again what's wrong with the lee under size die?

 

I use RP cases and don't have the issues you are having.

Edited September 10, 2020 by AHI

[limitedgun]

On 9/9/2020 at 7:33 PM, atblis said:

Regarding the Lee FCD, wouldn't I then effectively resizing the bullet too? 

 

When in doubt, start measuring (done with good calipers, not a mic so...)

 

Bullet that set back under finger pressure measures 0.400" (as do several others)

Wall thickness on offending R-P case measures ~0.011" (measured using tubing mic)

Wall Thickness on other headstamps meaures 0.012"+

Loaded round measures 0.421" OD (the case that setback easily)

Regular Lee die measures at 0.417"

U Die measures 0.413"

M die expander measures at 0.498"

Case sized in regular Lee die measures 0.420"  OD

 

I think it's R-P cases that are the problem. Doing a little more reading on the internet, there's a good bit of bitching about the R-P cases. It sounds like they get a little work hardened after a couple loadings and lose neck tension (being on the thin size contributes). I am surprised they spring back that much.

 

Hmm, don't want to sort my brass. ~Half are R-P cases.

 

 

 

 

 

 

 

 

 

This argument justifies using the Lee U Die which you claim is too tight. You have made a statement the U Dies is too tight with no supporting evidence except your opinion. I have been loading 40 since 1992 (over 120,000 rounds) and have never had this problem. WHen I started loading there was no U Die, no Case Pro, no Factory Crimp Die. These things have all made for improved loading over the years, but they cannot fix all. They did a great job reducing rejects. I have never seperated cases. Just adjust your dies correctly and get to loading.

[Kilrb]

I went from an RCBS die to the Lee, have had fewer rejects with the Lee since I started using it a couple of months ago.

[Farmer]

1- You can either just size with the Lee std die and then partially size with the U-die beings you already have both.

2- Reduce the size of you M die on the end for less expansion.
3- Trade your Rem brass for something else. 

A Lee FCD won’t even touch the case because of it’s thinness. 

 

[Yeti]

Buy the EGW version (made by LEE sold by EGW) which is only 0.003" undersized.  Yes, it cost more. 

I find the standard less expensive LEE branded U-Dies are too undersized.

[Chris51080]

Im a little confused, maybe some clarification is in order.

I'll start with my process, and you can let me know where it differs from yours.

 

I use range brass, whatever we pick up in 40SW, or whatever I buy from various online sources. Its all used brass. I don't bother to sort it beyond verifying that it is 40S&W.

 

I use the EGW Lee Undersized die. 

- Note that this does mean I can't simply slip a bullet into the brass at this point. 

 

After priming of course, I move to my Powder drop, with a powder thru expander. This puts a slight (adjustable) bell on my resized brass. I set this up so it is just enough to get the bullet into the brass without scraping the poly coating off.

 

From there, I seat my die to depth.

 

My final stage is a Lee Factory Crimp Die. This removes whatever is left of the bell and ensures that the brass has the proper hold on the bullet.

 

I have had no issues with this process, and only split the occasional case that has been fired numerous times.

 

What problems are you having?

What makes you believe that the brass is too thin?

I don't use case lube on my pistol brass, mainly because my sizing dies are all carbide. That being said, if I do have any issues, a little lube will help.

[Jim Watson]

1.  Use the U die and squeeze them down.

2.  Shoot them in lost brass matches.

[427Cobra]

I bulge bust every 40 case, I full length resize with a Lee U die, my Infinity eats my ammo, and is accurate, IMHO the FCD is un needed and makes ammo less accurate. 

[Ming the Merciless]

1 hour ago, Chris51080 said:

My final stage is a Lee Factory Crimp Die. This removes whatever is left of the bell and ensures that the brass has the proper hold on the bullet.

 

 

Actually the Factory Crimp Die only ensures the outside brass dimensions.  It does not ensure the brass has a proper hold on the bullet especially with lead bullets.  When the FCD squeezes the brass, the brass will spring back a small amount.  The lead bullet is squeezed by the brass and lead does not spring back.  Depending on hardness and diameter of brass and bullet I've seen the FCD increase Over All Length as the case is pulled out of the die by the FCD squeezing the bullet up out of the case.

[AHI]

3 hours ago, Yeti said:

Buy the EGW version (made by LEE sold by EGW) which is only 0.003" undersized.  Yes, it cost more. 

I find the standard less expensive LEE branded U-Dies are too undersized.

According to Lee and EGW  they are (both ) .003 undersized

[Matt1911]

EGW U die has fixed all of my previous problems loading .40 ammo. 

I've never thought it was too much undersized. They all fit the case guage perfectly. 

[Kilrb]

On 9/12/2020 at 4:36 PM, AHI said:

According to Lee and EGW  they are (both ) .003 undersized

They are I ordered EGW, got a Lee from them

[bigedp51]

The more the case is resized and reloaded the more work hardened the brass becomes. This causes more brass spring back after sizing and less bullet grip.

The undersize dies reduce the case diameter more to counteract brass spring back and less bullet grip.

Below is a 9mm cartridge sized with a under size die and the case is wasp waisted that increases bullet grip. (this is good)

Two things pistol shooters never do, trim their cases and anneal their cases to make the brass softer. So use the under size die and "Get a grip".