Do you recommend using the Lee U die for 40S&W?

[RePete]

10 hours ago, workingmanjeff said:

This, I use the egw version for 40 and 9

They were mafe by Lee for EGW.

[ULshooter2491]

Yep. Use the Lee undersize and Lee FCD. Made a world of difference on range pick up brass not case gauging 

[427Cobra]

I use the EGW/Lee undersize die for 40 loading for my Infinity, I also bulge bust every single piece of 40 brass because I only use range brass, on the plus side I have never had a ammo related issue, my ammo is accurate, and no case gauging, downside is time bulge busting.  

[HCH]

Never used their U die, but I do use the factory crimp. 
 

the only times I seem to have a problem is with a split case. 

[synchronicity]

I bulge bust and use the undersize die for .45 acp & GAP.  I use just the undersize for .38.

Note:  This is for 100% reliability in the 1911, and unrivaled speed reloads in the revolvers.

I have experienced NO negatives whatsoever.

 

[synchronicity]

And everybody gets the FC die.

I have had GOOD luck using LEE for everything from .380acp to .50BMG precision.

[CHA-LEE]

Roll Size or Push Through size your 40 brass to eliminate the belly on the bottom of the case. Then use standard Dillon sizing die while reloading. Doing this creates a much straighter case sidewall which dramatically reduces nose dive style jams and other feeding inconsistencies. Undersize dies create a coke bottle shape in the brass which is detrimental to feeding. You can also NEVER get an Undersize die to go completely to the bottom of the case while reloading so there will always be a belly at the very bottom of the case. This also promotes the coke bottle shape in the brass.

 

Yes Roll Sizing or Push Through sizing brass takes time and is another brass processing step before you can reload it. Its well worth the investment in the long run due to the dramatically reduced feeding issues that you will experience.

[michael b.]

I'm going to change my input from my earlier post.  While Cha-Lee is certainly more knowledgable than me, I will piggy-back on what he's saying.  

 

I switched to a manual rollsizer in the few weeks since my previous post.  Its made a world of difference, as Cha-Lee has explained.     

[Sig]

I haven't found a need for it in 40.  I'm using the U die with my 9mm jacketed as I wasn't getting enough neck tension with Federal & Blazer brass.

[sanjiro]

Works great.

[chatsayson]

Been using it and improved my sizing. I have to use one shot though to be easier on the insertion.

[Guitarmageddon]

Yep use it exclusively in 9mm and 40. And if you want to add an extra prep process, you could run through a Lee/APP bulge busting step, which is a push through base size versus the rollsizer.

 

People complain about "coke bottle" effect but this is literally a non issue and moot point. Dillon 9mm dies will coke bottle, depending on bullet diameter, but it doesn't make a difference.

 

The u die does work the brass a bit more so you will get some brass shavings at the belling step but that's the nature of the game with undersizing. The case can be made there to use lube if you don't already (I don't). And as others have said, on a progressive press since the opening of the die is smaller (thus to undersize the brass) the case sometimes doesn't line up just right as you run up the brass and it take a wiggle or two, but this doesn't happen much.

 

Additionally , if you like to shoot blue bullets who by standard sells undersized bullets for 9mm and 40 (.355 and .400 respectively) you will find a benefit to undersizing and giving yourself neck tension. If you religiously use .356 and .401 then the neck tension benefit of the u die diminishes a little bit but then you still will likely want another method to make sure there are no low base bulges.

 

Resort to the Lee FCD as a last measure until you have tried other methods of correcting issues. It almost always will swage your projectile and almost always will introduce the ability of the finished round to set back by way of taking neck tension.  The one useful purpose of the FCD is it's role in the bulge busting kit however, if you do that processing step.

 

One anecdotal note, I tried a 45 u die and for that caliber it had a high degree of split case mouths both on the press and after firing. I think for that caliber it just works the brass a bit too hard. In 9mm and 40 though, it's a damn good piece of kit and should be on your press.