Leaving false shoulder for fireforming?

[arthurj]

Hey guys, I am going to a 6.506AI built. I have bought a FL 270 die and a 6.5-06 die for necking down lapua 30-06 brass. I am wondering about leaving the false shoulder to give the crush fit for fireforming. What I am wondering is, if the gun will have a tight neck, how do I turn the necks when leaving the false shoulder? Surely I wouldn't neck down, turn then neck up, then back down leaving the shoulder? That seems like too much work on the brass. Do I need to turn while the neck is .270 or .30 caliber diameter then size down? If those who form off of the false shoulder for a tight necked gun could tell me the process they go through, it would be much appreciated.

 

[4ked Horn]

Oh that is easy. First I would...

ACTUALLY I would, no, wait, that ain't right.

Hmmm?

Well you could probably...

Um, nope.

Hell, I don't know.


/ubbthreads/images/graemlins/grin.gif

 

[Wild_Bill]

Ok here is how i do what you are trying first neck to 270 making the case a tight fit on a false shoulder then to 25 cal again a tight crush fit. Trim all cases to the same length then neck the case on the apropriate mandrel for turning and cut the neck so the cutter finishes right at the false shoulder and not relieving the crush you will get well formed cases with perfect necks. The most important thing is triming the cases as this uniforms the length of the neck turning. Take your time setting up what you should do is set up a few with old 30-06 cases to try the procedure and set the dies and turner before atempting your good cases. Realy when you have a false shoulder on a case it is exactly the same as turning a case without false a shoulder as you just turn up to the factory shoulder dont worry just take your time.

Cheers Bill
Australia

 

[arthurj]

Thanks, how much of the false shoulder do I leave? Or do I need to wait for the gun to know that?

 

[screech]

Beginer question, whats a false shoulder

 

[jb1000br]

Fals shoulder FF'ing... http://www.6mmbr.com/6improvedform.html

JB

 

[Fiftydriver]

Arthurj,

If your smith knows what he is doing( /ubbthreads/images/graemlins/grin.gif) you will not need to worry about this. Keep the shoulder angle consistant with the original shoulder angle and the chamber will be set up with the proper crush fit as is.

YOu may want to send some necked down cases to be used to set up your headspace to those cases with the proper crush fit.

Only time you need to use a false shoulder is when your dealing with a case design that moves the shoulder position forward or when a chamber is not properly set up in headspace measurement.

Again, if your smith knows what he is doing this will not be an issues /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif!!

Kirby Allen(50)

 

[arthurj]

Thanks Fifty, I was hoping you would chime in with an answer like that! Good I will send you some cases when it gets closer to go time. One other question to see if I am on the right track. So now when I am necking down and trying to keep that shoulder angle consistent I will need to set up the 6.506 die so that it sizes all of the neck but without touching the shoulder. I have just played around with it and it seems that there is a very specific die setting that will neck down the case without touching the shoulder or leaving a small "hump" In other words leaving no false shoulder?
Thank a lot

PS I know this project is still a good time away but I'm too excited, I've got to be doing something with it! I figured I could at least prep some brass every now and then!