Doughnuts inside case neck

[alinwa]

Scott,
By reading his post on the other website, it seems to me that, what alinwa did was spec a reamer that forces the case to expand in diameter on the base, thereby causing any excess brass to flow to the thin side. Seems like a high risk move that is heavily reliant on the reamer not being a tenth too large or the brass not being too thin to start with (as in Winchester brass). Not to mention that altering a standard chamber is not an option for F-TR shooters like you.

Alinwa may succeed in delaying/eliminating donuts at the expense of brass splitting. He refers to this as culling the brass. In my opinion this seems like a cure that is worse than the disease, but if it works for him in benchrest, wonderful. Like my mother used to say "There are many roads that lead to Rome". He has not defeated physics.

Common problems have common solutions. I have a system that makes donut removal simple and painless. Sounds like you have a wide neck that makes neck uniforming/turning unnecessary. It's all good. Let's all be friends and sing "Happy New Year" together.

Kindest regards,

Joe

Wow, just WOW......

this astoundingly ill-informed piece of illogic illustrates perfectly why I don't play chess with pigeons.

Scott,
By reading his post on the other website, it seems to me that, what alinwa did was spec a reamer that forces the case to expand in diameter on the base, thereby causing any excess brass to flow to the thin side. Seems like a high risk move that is heavily reliant on the reamer not being a tenth too large or the brass not being too thin to start with (as in Winchester brass).


Kindest regards,

Joe

Statements like this also illustrate yet again to me that I can NEVER and will NEVER prepare to plumb the depths of human ignorance!! Just when I think I've managed to provide an explanation that ANYONE can understand, along comes kindly Joe.....

Let's us just examine Joe's "logic" shall we?

........... what alinwa did was spec a reamer that forces the case to expand in diameter on the base, thereby causing any excess brass to flow to the thin side. ..........


Kindest regards,

Joe

wait, alinwa did WHAT???

!!!!!

OK, to all who're reading this, what Joe is referring to is an obscure reference buried in PAGES of explanations wherein I talk about increasing or blowing out the body of a .473-based case an extra 3 thou in the interest of eliminating extraction "click" (which I DO BTW) and from this kindly Joe extrapolates that I'm "thereby causing brass to flow to the thinnest side"..... a "high risk move".......

Joe..... JOE, you silly bint..... this is less movement than the amount the necks of your factory cases move EVERY TIME THEY'RE FIRED, REPEATEDLY......... (and I'm a guy who routinely blows case out from .243 to .308 or .338 in one pop!)

And "excess brass to flow to the thin side"...?????

JYPers...... I can't possibly make this stuff up!

I won't go on as the rest of your "conclusions" are equally flawed but, for posterity, to all reading this, this is like a a kindly hillbilly watching Apollo lift off and opining that "What NASA have done here is developed a high-risk method of blowing debris off the concrete pad they park their rocket on"....

Daily I'm amazed that companies dare continue to sell "reloading manuals" and components to people on the street.

It's a dan'rous world out there folks..... lions and tigers and bears Oh My..........BE CAREFUL where you get your information.

 

[alinwa]

Well, I don't think we need to debate about how or when brass flows...it does flow...and forward. Everybody has to size their brass and everyone has to trim it and everyone will get donuts sooner or later. If you want to mitigate or prevent donuts, then use a neck turning tool with a cutter to match your shoulder angle Then, cut a healthy amount out of the neck/shoulder junction. With proper cutter, this virtually eliminates the donut issue without causing any neck separations. I never had a neck separate doing this and the donut problem is gone for....the life of the brass. Or, you could just use no-turn brass and get your freebore such that the bullet is never close to the donut. That would be the way to solve this problem with a lot less work! We use about .250 FB on our 284s and it works like a charm. Have converted a bunch of people over to the dark side (no-turn) and they have been very pleased (and surprised) with the results.

Ohhh yes, and the inimitable Scottie.... let's us not leave anyone out.....

Y'all are in good hands here kiddies with Uncle Scott and kindly cousin Joe......


Just you scamper on out into traffic now and look for them coins now, the big road with the fences downside is BEST! You'se climb over or cut the fence and get out there, get them nuggets before the cars run over them and scuff 'em up....

I be SAVE these posts eh.... mebbeso print 'em out! put that big one with the pixture of the pile of brass and the part about "making up facts" in it right up on my wall!


wheeee

 

[alinwa]

You are entitled to your opinion, but not to make up facts.

Yes, theoretically if I take a large cylinder and compress it to form a narrower cylinder the wall thickness has to increase. So I will give you that, but that is only in theory. In the real world things are more complicated.

Most virgin brass manufactured necks have as much as .003 differences in neck walls and will easily fit in a SAAMI chamber with simple neck sizing and generally will have excess head space. It isn't unusual for Lapua or Norma brass to have .005 or more of head space. Sometimes its even more and I have to jam the bullets to keep the brass from being pushed forward by the firing pin therefore failing to fire. That's why most competitors don't take virgin brass to matches, it isn't fire formed to the chamber. After the brass has been fire formed most of us precision shooters only push back the shoulder a couple of thousands. After pushing the shoulder back .002 it is still forward or where it was when in its virgin state. So your claim that pushing the shoulder back creates donuts is false.

I uniform (I think the term "turn" hides the real purpose) my virgin brass, and after I've fired the first time I uniform the necks again. Guess what happens? More brass is removed. Where did it come from? Pressure, 60,000+ psi, and heat drove it forward. Why? Very simple, that's where the pressure release is. Brass flows forward, because ignition starts at the case head with primer blowing everything forward because of heat and pressure.

Yes, Ackley Improved cartridges reduce brass flow, that is the main benefit of AI, because the 40 degree shoulder provides more support to forward pressure. However, it doesn't eliminate it. I know I have 260AI.

In theory one should be able to ream a donut out of the case, in reality that is not practical because getting the geometric dimensions just right (wall thickness, and neck size) is beyond the ability/finances of most reloaders. So, the best most of us can do is push the donut to the outside and remove it with a neck turner.

The higher the pressure you run, the more likely you are to have a donut. If you can seat the bullet forward of the donut, that's the way to go. But, remember heat and pressure drive brass forward and with enough firings the brass will move to your bearing surface and affect neck tension, bullet alignment and bullet release.

Kindest regards,

Joe

View attachment 1081026

I had to preserve this....

 

[AlNyhus]

Can doughnuts form by full length resizing?

In short...yes. But it's not always that simple. And sometimes it is.

The whole 'donut' situation can also include the die/chamber dimension, how the necks were turned, how the shoulders were blended during the turning process, case material issues, the true amount of shoulder setback during sizing, etc, etc.

Having a true, round neck I.D. that is both concentric to and parallel with the outside neck is what I found to work.

Good shootin'. -Al

 

[JFrank]

Gosh
I'm again the minority with no Donuts.

I don't turn necks
I don't anneal brass
I do use quality Dies
I do use quality brass
Humm
What have I done wrong?
J

 

[AJC]

Gosh
I'm again the minority with no Donuts.

I don't turn necks
I don't anneal brass
I do use quality Dies
I do use quality brass
Humm
What have I done wrong?
J

It maybe that your process is good, your not running stupid high pressure, your dies match your chamber well, or just lucky. Dont question good luck

 

[Rem6br]

I have donuts anybody want some?

 

[antelopedundee]

Does the donut problem arise if one has nickel plated cases?

 

[AJC]

Does the donut problem arise if one has nickel plated cases?

Very intrested