How Much Neck to Size?

[walker2713]

When preparing the brass for fire forming for 6 Dasher or 6 BRX, using the "false shoulder" method, how much of the neck needs to be re-sized by the 6BR die, after expanding the neck to .264? I'm using a Wilson neck die. Thanks. George

 

[22DASHER]

Just enough so you can close the bolt with a "snug" crush fit...

 

[wiuprof]

When preparing the brass for fire forming for 6 Dasher or 6 BRX, using the "false shoulder" method, how much of the neck needs to be re-sized by the 6BR die, after expanding the neck to .264? I'm using a Wilson neck die. Thanks. George

I'm curious why you go "up" to .264"? I use a .257" expander mandrel and it works great.
Here's a photo I posted a few years ago, showing the slight false shoulder.

 

[savagedasher]

I like to use heavy flat base bullets when fire forming . My necks finish longer and the shoulder is better. Sorry for the hi jack.
Larry

 

[dmoran]

I'm curious why you go "up" to .264"? I use a .257" expander mandrel and it works great.

Myself I used a 257 false shoulder for a few years and several hundred brass, and then one day I tried it with a 264 shoulder. I like the 264 shoulder better, and get a little more consistent "blow lengths", no doubt do to the little extra crush you get with a 264 shoulder that holds the case against the chamber wall a little better, allowing less shove from the firing pins strike.
My 2-Cents
Donovan

 

[walker2713]

I like to use heavy flat base bullets when fire forming . My necks finish longer and the shoulder is better. Sorry for the hi jack.
Larry

No problem...thanks for the suggestion....

 

[walker2713]

I'm curious why you go "up" to .264"? I use a .257" expander mandrel and it works great.
Here's a photo I posted a few years ago, showing the slight false shoulder.

I'm curious why you go "up" to .264"? I use a .257" expander mandrel and it works great.
Here's a photo I posted a few years ago, showing the slight false shoulder.

Because that's what I have....thanks for the great photo...very helpful.

George

 

[XBBR Shooter]

Myself I used a 257 false shoulder for a few years and several hundred brass, and then one day I tried it with a 264 shoulder. I like the 264 shoulder better, and get a little more consistent "blow lengths", no doubt do to the little extra crush you get with a 264 shoulder that holds the case against the chamber wall a little better, allowing less shove from the firing pins strike.
My 2-Cents
Donovan

I also like a larger false shoulder for the same reasons.

 

[walker2713]

One of the reasons I originally asked the question is that I was thinking about sizing down to .243 only enough of the neck to grip the bullet. Using a Wilson neck die with Redding titanium bushing, I am thinking about putting washer/s on top of the die, adjusting number and size depending on how far I wanted to neck back to .243. The washer would require a .47"+ inside dimension and approx 1" OD.

Comments?

 

[dmoran]

If you have a lot of false shoulder, it can make bolt closer very hard or even impossible. Anything more then about .030" of actual crush, can make it forceful for closer.
Myself I like to have at least .020" of crush (some force needed for bolt closer).
Donovan

 

[shoot4fun]

I also use a .264 expander mandrel. For determining how far down to size the neck for fire-forming I use my Redding Competition Neck Die for 6BR and a proper bushing for 6MM bullets. I can slowly set it for a very tight crush fit. Once I have the false shoulder in then, and this is something others may disagree with, I neck-turn the brass down onto that false shoulder. I only turn about .0013 or so to clean it up but prefer doing that before the shoulder is blown out to 40 degrees.
I would say your idea about using shims to precisely adjust the Wilson die will work fine.