Neck turning a doughnut?

[Link]

When running a mandrel in a well fireformed BRA case we get a donut on the outside of the shoulder neck junction. I assume we can turn that down to neck OD with no ill effect. Am I right? I can live with it, its not that bad but I would like to clean it up if I can.

TY
Don

 

[JSH]

Turn it off.
I tried dunking them in coffee, but they just wouldn’t go away;-).

 

[PopCharlie]

Turn it off.
I tried dunking them in coffee, but they just wouldn’t go away;-).

Dunking them in a 20 year old single malt scotch works, but not till after the 3rd glass.

PopCharlie

 

[jepp2]

Any body try the K&M carbide cutting pilot to cut it off inside the neck?
https://kmshooting.com/product/carbide-cutting-pilots/

 

[JSH]

If I do everything what I deem right, I take a skim cut on the neck just to knock off the high spots (depends on wanted end neck thickness), then hit the donut.
Two birds with one stone so to speak.

 

[smithcollector]

Forgive my ignorant question: if I’m running a mandrel down the neck, pushing the donut outside, can I just leave it if no interference with chambering the round?

 

[SeabeeKen]

Is it affecting your accuracy?

 

[GunzRUs]

Forgive my ignorant question: if I’m running a mandrel down the neck, pushing the donut outside, can I just leave it if no interference with chambering the round?

Therin lies the problem which I found out the hard way...mandrel does push donut out making chambering a little tough so neck turned donut out and no more problems

 

[rwj]

Therin lies the problem which I found out the hard way...mandrel does push donut out making chambering a little tough so neck turned donut out and no more problems

An option to turning is to adjust the mandrel’s insertion depth to be just past the location of the bullet’s pressure ring...

 

[DJSBRS]

Be sure to use the correct angle cutter to cut away the correct proportion of the donut without cutting the neck shoulder too thin.

DJ

DJ's Brass Service
205-461-4680

 

[ronemus]

Inside reaming a donut is difficult to do precisely because the reamer OD has to match the neck ID very closely to do a good job; any mismatch can severely damage the neck. It's a lot easier to neck turn precisely, especially if you still have the turning tool set from the original turning of the neck.

 

[Richard Coody]

Use the right cutter turn them off and cut slightly into the shoulder. That shoulder brass is thicker and is migrating into the neck. Using a bushing die makes it worse.

 

[searcher]

When you run the mandrel into the neck to "push" brass flow to the outside, it helps greatly to do this after annealing the brass. If you don't anneal, you will see diminishing returns in your efforts as the brass becomes more brittle with aged firing and it takes on a tendency to just "spring back" once the mandrel is extracted. Still, you are correct in that some brass will be pushed to the outside where it can be neck turned off by cutting into the neck slightly with the correct angle cutter so as to provide a space for the remaining "spring-back portion" to flow into once fired again. You can also use an inside neck reamer to remove the brass, though the process is a bit trickier.

 

[JohnD]

I now use a Lee collet die to size my 6XC brass after using a bushing die for the first 3-4 firings. I can tell when a piece has a doughnut buy the resistance on the mandrel and also buy inserting a bullet in a fired case. I simply back the neck cutter off on my K & M and let the carbide mandrel cut the doughnut out. It seems to work for me and I've not seen any problems.

John