Donut removal

L

Lucky Shooter A

Guest
I somehow created donuts in the transition from 221 FB to 20 VT----used Redding bushing dies for the first step in case alteration.

I've always used the expander to force the donut to the outside-----and then trim it off while turning the neck.

I use a K&M turner and they recommend partially expanding the neck-----down to just short of the donut-----and letting the cutter on the neck-turning pilot cut it out on the inside. Its not very obvious to find the spot where the expander should stop just short of the donut.

Anybody have any comments on donut removal ?


Thanks for any replies.

A. Weldy
 
Lucky Shooter A said:
I somehow created donuts in the transition from 221 FB to 20 VT----used Redding bushing dies for the first step in case alteration.

I've always used the expander to force the donut to the outside-----and then trim it off while turning the neck.

I use a K&M turner and they recommend partially expanding the neck-----down to just short of the donut-----and letting the cutter on the neck-turning pilot cut it out on the inside. Its not very obvious to find the spot where the expander should stop just short of the donut.

Anybody have any comments on donut removal ?


Thanks for any replies.

A. Weldy
Click to expand...

I think the way you are doing it, that is, allowing that "hump" to be removed during neck turning is the most vialble way.

But, keep in mind. Any time you neck a case up, or down, and change the shoulder to neck transition, there is always a possibility that a donut will form at that point after repeated firings.

As far as donuts go, as long as the straight portion of the bullet does not encounter it, is it really a problem?
 
How are you determining that you have a doughnut? Usually when necking down, part of the neck becomes part of the shoulder which is the opposite of what forms a doughnut. In any case, if the full diameter part of the bullet is not in the area of the doughnut it is of no consequence, unless you are routinely using a expander ball, in which case it can be an issue.
 
Donut---thanks

Jackie & Boyd,

I'm currently seating my bullets (flat base) long enough for the base to clear the donut-----will have to deal with the donut if I need to seat much deeper.

A bullet will drop easily into a fired case neck but will stop before falling through. A little measuring and simple arithmetic indicates the stopping point
is at the shoulder/neck junction.

243winxb,

I've read that the bushing die is a contributor to the donut and that I might do better with a conventional sizing die----I have no way to compare since I only have the bushing die.

Thanks for the help.

A. Weldy
 
If you think about it for a bit, when you used a bushing die to neck down, the base of the neck including the ID was left larger than the rest of the neck, and unless your pre turn expander was larger than the ID at this point, turning to the shoulder would have resulted in the neck being thinner in this area. Did you turn solidly into the shoulder. Did you move the shoulder back when you necked down? That could cause a doughnut. Working with two different shoulder angles can fool you sometimes.
 
Boyd

I planned not to have to turn necks on this one-------before realizing the donut must be dealt with. I haven't yet tried to remove any brass, inside or outside.

I don't think the shoulder was set back-----no actual before and after measurements to back this up, however.

I think I can live with this as-is unless I need deeper seating of the bullets which make contact with the donut.

Thanks.

A. Weldy
 
Last edited by a moderator:
jackie schmidt said:
I think the way you are doing it, that is, allowing that "hump" to be removed during neck turning is the most vialble way.

But, keep in mind. Any time you neck a case up, or down, and change the shoulder to neck transition, there is always a possibility that a donut will form at that point after repeated firings.

As far as donuts go, as long as the straight portion of the bullet does not encounter it, is it really a problem?
Click to expand...

Well, it can be a problem if you're using a hand decapper for some reason. I discovered some doughnuts in my 6 ppc brass when I used my Neil Jones decapper on them.
 
Try using a chucking reamer the appropriate size on fired cases. You can remove 90% of the donut without touching the ID of the neck.
I'll add. Depending on neck clearance in the chamber, all you need is one a couple of thousandths over bullet diameter to get clearance for the bullet.
 
Last edited:
Dave Tooley said:
Try using a chucking reamer the appropriate size on fired cases. You can remove 90% of the donut without touching the ID of the neck.
Click to expand...

Reguardless how you prep your cases a donut will form after a few firings. Even though most bullets and settings the bullet never hets to the donut that forms at the neck shoulder junction that obstruction does SEEM to effect the accuracy of that lot of cases.

I have a reamer that fits in my case trimmer that reams the donut without reaming the neck an trims case length at the same time. On older cases that have been fired several times (probably over 15 firings or thereabouts) they DO shoot more accurately. Does the donut reaming, the trimming to length, or both rejuvenate these cases? I don't know. Has anyone of you tried this?

.
 
A little more

Jerry, Dave,

I hope I'm headed down the right path with a K&M neck turner with a cutting pilot.
This pilot has a diameter of approx .2035"----which removes only part of the obstruction
and leaves an opening smaller than bullet diameter.

A few of these cases have been fired and the donut hole will pass the .2035" cutter but still
obstruct a bullet-----a least the donut holes will be more uniform.

I think I'll be in good shape if K&M will supply a slightly larger cutter----and possibly a larger
matching expander.

Thanks for your help.

A. Weldy
 
You must log in or register to reply here.
Back
Top