wHO USES A LEE COLLET DIE ON NEW UNFIRED BRASS????

martin

Beginner
Feb 18, 2012
4
0
I know how to setup and use my lee collet die on my RCBS press to achieve low runout on fired brass.

However I have bought some new brass and was thinking of using the lee collet die on the new brass. SHOULD I ?????

or load up some new test loads and just go to the range and fire form them to match the chamber. then use the lee collet die on the newly fired brass????

or last option Full length resize (or neck size with RCBS neck dies )the new brass ending up with runnout from my RCBS dies and load up some new test loads and just go to the range and fire form them to match the chamber. then use the lee collet die on the newly fired brass?????

Concentricity and less run out is the goal and minimal group size is the prize.

Buying Premium brass is not really an option for me.

THANKS IN ADVANCE
MARTIN
 
Using the LCND on unfired brass isn't going to do anything more than straigtening out of round necks... same as FLS'n brand new cases, for that matter, just not working the brass at all.
 
but I will end up with less runnout in the neck. and more concintricity. Correct????
 
makes sense to me have you measured the runout before and after the lee collet die???

THANKS FOR THE REPLY
MARTIN
 
martin":jv2eek02 said:
but I will end up with less runnout in the neck. and more concintricity. Correct????

Yeah, I suppose that if the alternative is a dented neck, you're right for sure. Sorry I wasn't sure exactly what you were getting at.

Personally I've found best results after initial fireforming of the cases to my chamber and a run through the collet neck sizer.

My regimen runs like this: w/ new brass (usually accompanies a new rifle) I will put together experimental loads based upon recommendations from people on sites like this (consulting manuals for safety, of course) just to get an initial idea of what certain bullet/powder combinations are capable of. That narrows things down for the real nitty-gritty testing that comes after fireforming.

I'm going to be doing this w/ my boys' new .243 Win, some Nosler custom brass, and Berger 95 gr VLDs...

Good luck! One thing I know we'll agree on... Lee Collet Neck Sizers RULE!!!
 
Hi Martin,
I have found that if I compare fire-formed brass to virgin brass, I have found headspace off the shoulder to be sometimes .012 and greater. Full sizing will not correct the virgin brass in this respect.

Neck concentricity can be corrected via turning but I am not sure of the percentage result on virgin brass. From my experience, I have not seen a true correction in concentricity by using the Collet die on virgin brass.

I am going to side with efw. I believe you can find some ladder powder charges and possible max powder throw, but I have not seen any great benefit from using the FS or Collet dies before fire-forming. Correcting dents and neck mouth bends can be beneficial.

My $.02

Thanks
338winmag
 
use caution when using a collet die on unfired brass , you can crush your new brass . I think what happens is the neck will fit the mandrel tight enough to close the collet jaws before the neck is inside the the jaws . causing you to push the brass into a closed collet . if you are going to do this to round out the necks , only push the brass into the die about half way . a fired brass case has the neck expanded a couple thousandths allowing the brass to go over the mandrel without any resistance . this allows the collet jaws to remain open to accept the brass neck . Jim
 
Everytime

I never had a problem not being able to get the mandrel into the neck of new brass. IMO it will do 2 things

  • Uniform the neck
  • Set the bullet grip at about .002" (sometimes new brass can have a lot of bullet grip)

But the Lee Collet will not correct runout, it just doesn't make any new runout. IOW when you fire the brass in your chamber it will come out with very little runout and the floating mandrel in the Lee Collet will center and not push the neck to one side or the other. OTOH if you already have runout, it will not correct it.

The only caveat is that if you have new Nickel plated brass, don't use the Lee Collet
 
Woods mirrored my response exactly. Besides ironing out any dents, it also keeps neck tension consistent from first firing and so on and so on. Though after a few firings necks will need to be annealed to retain the same amount of spring back.

If I want more or less neck tension on the bullet I'll order a couple of extra mandrels from Lee and either have them reduce the diameter to a requested amount or do it my self.

Alan
 
"Set the bullet grip at about .002"" & "also keeps neck tension consistent from first firing"

Oh man! good points guys. I forgot about those!
Woods! Great to see you!!! You are a rocket scientist. :grin:

338winmag
 
Coffee%20Mug%20-%20Far%20Side%20Rocket%20Scientists.jpg
 
Back
Top