Sizing part of the neck on turned cases

[distantfoe]

Will this eliminate problems with doughtnuts?

 

[tightneck]

As long as you're not seating the bullet into the donut, forget about it.

 

[paulT]

If the bullet is seated into the sholder junction for best accuracy should all the neck be necksized, regards paul.

 

[mikecr]

If you seat the bullet into the neck-shoulder junction, neither FL neck sizing or partial will make any difference,w/regard to any doughnut). The bullet expands the neck to what it's gonna be.

One way I eliminate a chance of doughnuts is to turn well into the shoulder and set the shoulder junction up higher in the neck with a fireforming,sacrifice a bit of neck length). It's built into the reamer design.

 

[distantfoe]

My problem shows itself when I FL size and try to seat a bullet, the bullet is stopped short by the doughtnut. I've tried turning well into the shoulder on unfired brass but the doughtnut shows up anyway.

I don't mind turning necks a second time. Although here's what really concerns me, my redding FL die just seems to be working only part of the neck. This leaves a small poriton of the neck "blown out" to be turned off. The result, a very thin portion of neck just above the shoulder.

I feel this is something to worry about as I don't want to blow the necks down the barrel.

Your suggestions are appreciated!

 

[USAPatriot]

Is this a wildcat or factory brass? -Rod-

 

[distantfoe]

I'm working on a 7wsm shooting 168 bergers. Normally this isn't a problem but all that I've shot to date have been significantly shorter bullets in longer necked cases.

 

[CPorter]

There is a theory that not sizing the whole neck will help the cartridge center in the bore better.The case neck should be about .001" under the size of the chamer neck after firing.

You do not need to be turning the unsized portion off the cases. It will thin out the neck and cause a separation. My Redding FL bushing die is adjustable as to how much of the neck you can size. If your FL die isn't sizing the whole neck and isn't adjustable it sounds to me like it isn't setup right. Is the die screwed down in the press so that the ram is just touching or <1/4 turn away from it? If is is setup properly then it was reamed wrong or it has worn oddly. If it is adjustable just screw it down some more.

 

[tightneck]

I own sveral Redding FL bushing dies. Not one of them will size the neck all the way down to the shoulder. If I need to size the entire neck, I use a standard FL die. I do this to several calibers prior to turning necks in order to set the shoulder back. Then when I go to turn the necks I can turn to the false shoulder, and upon fireforming the shoulder blows out to its final position. Now my cut into the shoulder has not created a thin spot for an impending neck separation. All that being said though will keep a donut from forming in the short term only. As Gunamonth pointed out, the brass flows from the shoulder into the neck with repeated firings and creates a donut. It can be outside neck turned off after the donut is pushed back to the outside of the neck with an expander mandrel. K&M no makes an internal donut cutter for use in their turners but I have not used one.