Removing Donut

[GSPV]

I bought a slew of 3-4 times fired 284 Shehane brass for a project.

Looks like the fellow that I bought them from didn't turn into the shoulder enough and there is a substantial donut.

Is there a sure fire way to remove it now? Or do I have to pitch it?

Thank you in advance,

 

[Steve Blair]

All my Shehane brass was neck turned into the shoulder. Every one, after two firings, has a donut. It never causes a problem because I seat the bullet shank away from the neck-shoulder junction.

 

[Lapua40X]

I'd have to concur with Steve's point. If it ain't causing a problem, forget about it. However, when it does develop into a problem (or if you're like me and just can't stand to deliberately permit an irregularity to exist) there are a number of methods for "fixing" the donut.
I prefer using a neck reamer. But I have a pretty good little mini-lathe; not everyone does. Using the neck reamer doesn't necessarily require a lathe but it does help in maintaining a nice straight cut down the neck.
Three things I try to remember about donuts.
1. If it ain't a problem, I jest fergit 'bout it.
2. I select a reamer that is about .002 - .003 under case caliber designation to avoid unnecessary thinning of the neck wall interior.
3. That brass didn't fall out of thin air. It came from another part of the case. So I monitor wall thickness etc. carefully with each reloading cycle.

 

[GSPV]

I'm afraid that I'm going to have to do something. The bullet that I want to shoot looks like it's right at the donut. I want flexibility to jump it . Think that I'll talk to Mike about getting a throating reamer.

 

[johara1]

I would use a K&M carbide mandrel and clean up the necks,it will remove the problem ……… jim

 

[thumper4fun]

I would use a K&M carbide mandrel and clean up the necks,it will remove the problem ……… jim

+1

 

[ReedG]

I do any donuts with a Forster case trimmer with a reamer .001 or .002 smaller than the bullet. This works well on fired cases, before resizing, and is a one-time task. The K&M "donut cutter" mandrel also does a decent job, but I prefer the Forster.

I'm not sure donuts are not a problem, even if not seating the bullet down to where they interfere. What about the different diameter of the hole in relation to the burning gases, etc.? I'm thinking there probably is an effect from "X" amount of powder burning in a case with, let's say, a .284 neck and the same amount in a case with a .282 or .280 neck.

I'm certainly no dynamics engineer and haven't any proof of any relationship. I just prefer to take care of one more "unknown" and it's certainly a simple task.

 

[johara1]

It is very simple, never seat the heel of the bullet past the sized part of the neck. …… jim