Neck sizing 6mm BR (Norma) with Lee 6mm PPC collet die question

[Chris Edmondson]

I learned about using a Lee 6mm PPC collet die from a few older threads here on AS, before I start neck sizing some brass, I'd like to see if others here who already do this can Yea or Nay my approach.

The main issue with using a 6mm PPC collet with 6mm BR brass is the base to the neck-shoulder distance of the 6mm PPC is less than the same distance for the 6mm BR; the difference is about 0.018". The risks are the collet may size into the shoulder, and it may not size the entire neck, the mouth area in particular.

The solution, as proposed in some earlier posts, is to use a shim washer between the shell holder and the die's collet. This will keep the collet away from the neck-shoulder, and cause it to size the entire neck. So, I made a shim washer that's 0.019" thick which I think will work.

Here's a picture showing what a 6mm BR case sitting in a #2 shell holder looks like inside a 6mm PPC collet:



The neck is clearly sitting proud of the collet, I don't think the neck-shoulder is in danger since the unsized mouth looks to be about the same when the collet simply rests on the case without the shell holder to keep them apart, still, it's a bit close for comfort IMO.

Here's a picture of the shim:



And here's what the case looks like with the shim washer in place:



The mouth is flush with the collet, maybe a hair below, the result should be to move the collet away from the neck-shoulder and to size the entire neck.

I know this is in arcane territory but, please let me know if my assumptions are incorrect, I'd rather not ruin expensive brass

 

[Hipshoot]

I learned about using a Lee 6mm PPC collet die from a few older threads here on AS, before I start neck sizing some brass, I'd like to see if others here who already do this can Yea or Nay my approach.

The main issue with using a 6mm PPC collet with 6mm BR brass is the base to the neck-shoulder distance of the 6mm PPC is less than the same distance for the 6mm BR; the difference is about 0.018". The risks are the collet may size into the shoulder, and it may not size the entire neck, the mouth area in particular.

The solution, as proposed in some earlier posts, is to use a shim washer between the shell holder and the die's collet. This will keep the collet away from the neck-shoulder, and cause it to size the entire neck. So, I made a shim washer that's 0.019" thick which I think will work.

Here's a picture showing what a 6mm BR case sitting in a #2 shell holder looks like inside a 6mm PPC collet:

View attachment 1690352

The neck is clearly sitting proud of the collet, I don't think the neck-shoulder is in danger since the unsized mouth looks to be about the same when the collet simply rests on the case without the shell holder to keep them apart, still, it's a bit close for comfort IMO.

Here's a picture of the shim:

View attachment 1690357

And here's what the case looks like with the shim washer in place:

View attachment 1690358

The mouth is flush with the collet, maybe a hair below, the result should be to move the collet away from the neck-shoulder and to size the entire neck.

I know this is in arcane territory but, please let me know if my assumptions are incorrect, I'd rather not ruin expensive brass

I use washers under a lot of my dies made of cardboard, different thickness plastic and odd and ends metal washers, for many reasons, mostly to partial size and not set the shoulder back. But for other reasons also.
just neck sized a .222 case in a .223 Lee collet die. Dies can be mixed and matched a lot of times just to get by.

 

[Murray Brook]

Been doing this for years. Set your collet die up the standard way. Size your 6BR case then insert your shim/washer ( mine is .089 ) and size again. Makes no ,difference if you shim/washer is too thick as long as it is thick enough. Job done. Works great. Oh and by the way you can't ruin your brass with a shim/washer that is too thin, just re do with a thicker one.