Neck turning vs reaming

[The Oregonian]

Maybe I am vastly oversimplifying this, but my understanding is that neck turning should be done on unfired brass - if done on fired and resized necks, you could get a donut at the next firing if the neck sizing operation isn't done perfectly at the shoulder junction.

Once brass has been fired, it is better to ream after firing but before sizing again.

Is my understanding accurate or is there something I am missing?

Thx

Tom

 

[MTBULLET]

use a lee collet die and don't fear the donut

 

[The Oregonian]

use a lee collet die and don't fear the donut

How much neck tension does the Lee give you? Wouldn't it depend on case neck thickness?

 

[Bill Johnson]

...don't fear the donut

That's funny

But seriously, I have once fired then neck turned brass on it's 7th loading and no donut. You simply have to put a small bevel on the leading tip of the cutter. You can do it with a rotary stone in a cordless drill. Too easy. Read this:

Neck-Turning Tool Cutting Tips within AccurateShooter.com

 

[Mikecr]

my understanding is that neck turning should be done on unfired brass

This is true. Brass pulled new from the box should be right for your turning sys expander mandrel, to create correct fit on the turning mandrel.

if done on fired and resized necks, you could get a donut at the next firing if the neck sizing operation isn't done perfectly at the shoulder junction.

Donuts initially show up on fireforming, when a bit of the thicker shoulder brass becomes part of the new neck. You have an opportunity to head this off when turning new brass, and this opportunity is past(missed) once fireformed.
There are folks who turn post-fireforming, FL sizing of necks, re-expansion or reaming, etc. I guess they like to challenge themselves..
But there is nothing good in FL sizing of necks, and hand reaming is not as accurate as turning.
It really is best to follow basic turning 101 with outside turning of new brass.