donuts

[rebs]

will partially sizing the neck help with reducing or preventing the donut

 

[LHSmith]

There are two forms of "donuts" in the accurate shooting world.
-One is a ring of carbon formed where the end of the cartridge lies in the chamber. Trimming cases much shorter than your chambers true case length will aggravate this condition.
-The other is a restriction formed inside the case neck near the neck/ shoulder junction caused from not cutting enough into the shoulder when performing the neck turning operation for using cases in a tight neck chamber. I use some Redding bushing dies ( which partial size the neck) in a few chamberings requiring tight necks and still have got donuts. Donuts are harmless as long as your bullet does not rest in the restricted area.

 

[fkimble@charter.net]

Never heard of a carbon ring referred to as a donut! But it is round and hopefully it still has a hole in the middle!

Frank

 

[Coyotefurharvester]

I like donuts, not a coffee drinker, milk instead. Never had a reloading/shooting donut.

 

[Richard Jones]

Never heard of a carbon ring referred to as a donut! But it is round and hopefully it still has a hole in the middle!

Frank

New one for me as well.

 

[Liven The Dream]

New one for me as well.

I think of Old Fashion Donuts with Coffee

 

[Whisky Tahoe Foxtrot]

Bushing dies tend to leave some unsized brass on the neck. I have switched to Forster FL sizing dies and have them honed to give me the neck diameter I want. No donuts. If you are using bushing dies, you can expand with either mandrels or gauge pins to uniform the inside of the neck. There's always some spring back so routine annealing when it becomes more of a problem.

 

[357Mag]

will partially sizing the neck help with reducing or preventing the donut

Rebs -

Howdy !

Please take as info only...

"Doughnuts" can also be a byproduct of a case' " wildcatting " process, when then parent brass is necked-down from the original calibre... to a smaller final calibre. The doughnut situation can be exacerbated when the wildcat case forming process also includes a downward " shoulder shove " on the brass.


With regards,
357Mag

 

[Straightshooter1]

will partially sizing the neck help with reducing or preventing the donut

The donut will still form, just it won't be in the way due to that part of the neck not being reduced/sized.

 

[rebs]

when I seat the bullet I have to seat long enough to stay away from the donut, right ?

 

[BoydAllen]

I think that some of us need some review on how doughnuts form. When a FL die squeezes the body of a fired case and we set the die to push the shoulder back the brass has to go somewhere....so a tiny bit of the brass that was at the top of the shoulder is pushed into the base of the neck, thickening it. This thickening is called a doughnut. The best way to avoid problems with doughnuts is to have a chamber design such that bullets' "shanks" (the full caliber part) do not make contact with the doughnut, or to shoot bullets that have a profile that has the same result. If your die barely reduces the body diameter of a tight case, and you set it to minimally push back the shoulder, doughnut formation will happen at its slowest rate. Conversely if you have a factory chamber that lets the case expand to something near SAAMI maximum, are using a die that is designed to produce SAAMI minimum for ammunition, and bump shoulders back more than is necessary, that will speed doughnut formation, and greatly increase case lengthening per sizing and require more frequent trimming to length. None of this is conjecture. I have had good measuring tools for a long time.

 

[rmist]

When I shot BR with the 6mmPPC every case was neck turned to thin the brass prior to forming from a 220 Russian case. Even after that you would still have a doughnut form at the neck shoulder junction. We used to internal reamer to ream them out. With a tool made for that purpose, hand use only no power tools. Brass flows from the case body outward and forms the dreaded doughnut. Wildcats are more susceptible to this. I've never had an issue using bushing dies on other cartridges! I shot the 308 WIn for several years only using bushing FL dies. Loaded thousands of them at higher than "book" levels and never had a doughnut form. Same with the 223 Rem.

 

[Link]

So ONE way you could tell if you have a doughnut is seat your bullet or mandrel deep into the neck and measure od at the top of the neck and the od at the shoulder junction. ?

 

[Sandstorm]

I ignore them and load my rounds above the donut. No issues here.

 

[snert]

when I seat the bullet I have to seat long enough to stay away from the donut, right ?

yes

 

[kochie]

yes

When necking down with bushing i always run a mandrel threw to get consistent sizing for my bullets

 

[DLT]

when I seat the bullet I have to seat long enough to stay away from the donut, right ?

Right

 

[Sandstorm]

Just seat above the donut and your ok.
The negative is you cant use a mandrel to open up the neck after sizing or you push the donut to the outside and interfere with chambering unless you dont go very deep.
You just need to work around them and your ok…

 

[chuckshooter]

I use an arbor die to push the donut to the outside, then if I feel the need, I will touch up the neck with my cutter.