The doughnut issue??

[Rtheurer]

Ok fellas I have to ask this. Like most everyone here with alot of loading experience I have delt with a Donut issue on brass in the Neck Shoulder junction. My first recollection was with 115 Bergers and JLK's in the 6SLR, seated with the Bullet Boat Tail /Shank (pressure ring) just a nats butt forward of above mentioned neck location. So I have been there and fully understand A. What it is. B. How it forms. And C. how to fix and avoid it.
What Im having a hard time with is that now for some reason EVERY Swinging richard seems compelled to imediatly blert out that....OMG you HAVE to stay ahead of that trouble point for EVERY cartridge we shoot. No matter if its a 308, 6mm Remington, 6BR, 6.5X47Lapua,260, 30'06, 7RSAUM, 300 WSM or what ever the case may be.
Sure we get some brass flow that is pretty Natural. But do we really really see it in some of these case we shoot or is it one of these things where it happens to one guy with some credability so everyone else jumps on the band wagon without actually experierancing the issue and by god its gospel now.
Is the sky really falling? Can you actually reload and shoot with out developing a donut?
I guess I dont see a donut in the 308 or 6BR and just have to ask..Not trying to be snyde by any means. We have such a wonderful cross section of seroius shooters here i thought I would ask.
Thanks for your time.
RussT

 

[Lapua40X]

Good point, Russ. I developed some donuts with my 6BR Norma which I attributed to some nearly max loads (because when I found the sweet spot with the lighter loads the donuts didn't form again) and I don't get donuts in any of my other rifles. I've read lots of theories about why the develop, how to remove them an whether or not it's even necessary to remove them at all. But emperical evidence to support what I've read or experienced hasn't surfaced in any of the articles.

 

[Alex Wheeler]

Theres a few issues with that area I am aware of. You cant control neck tension at the shoulder, if you dont size the whole neck you can avoid that problem. You dont want the pressure ring to go past the sized part of the neck, it acts like an expander and you loose neck tension. Now, if you actually have a donut formed then you definitely dont want the bullet to contact it, again you cant control neck tension with a donut. Now before you say I seat my bullets deep and my gun shoots fine, that doenst mean it is shooting as good as it can, or what your doing is the best for ultimate accuracy.

 

[LCazador]

The only time I ever had a problem with a donut was with my 6.5/284, thousand yard rifle. The only thing I did differently there was not cut into the shoulder enough when I turned the necks. I scrapped that brass, started out with a new batch of brass and cut a bit more into the shoulder and never had the problem again. When that barrel went out, I sent my reamer back and had it reground with a longer throat so I didn't touch that area again with 142's ;D ! I think it's a byproduct of neck turning, IMHO.

 

[Area Man]

In related news:

from ajc.com

Dunkin’ Donut thief shot by cop

An armed robber was caught in the act late Saturday at a southwest Atlanta Dunkin’ Donuts store, Channel 2 Action News reports.The suspect was apprehended after being shot in the arm by an Atlanta police officer at the Dunkin’ Donuts near the intersection of Ralph David Abernathy Boulevard and Cascade .

Robbing a doughnut shop? Need to pick a target where you are less likely to encounter a cop, maybe?

 

[BradY]

At the end of the day unless your seeing accuracy issues on target, why bother worrying about them? Sometimes you have to let the gun do the talking. If it works well, dont fix what aint broke. If you believe they are affecting your rifle/loads from performing then deal with them in due course. Anytime I neck up or down I expect donuts, but in all but one barrel I neck turn down and take a good cut into the shoulder when preparing the cases in the first place. Up well over 20 reloads in 260 improved that was formed from 308 lapua cases. No donuts. The only one I have seen it in is the 284 shehane with a no turn neck. I inside neck ream the donuts out, then on the advice from one of the winning Aus FCWC team members (who I think did very very well on the second day individuals) only size the top half to 2/3rds of the case neck so donuts arent able to touch the projectile anyway. Next shehane chamber will be 0.315 so I have to do a slight turn for clearance and a cut into the shoulder as well to avoid a donut forming.

 

[mikecr]

It happens when you upsize necks without turning to manage it. And it happens from a lot of FL sizing. That is, causing a lot of actual brass yielding with sizing, from webs upward to shoulders to necks(rolling brass thick toward thin-typical FL-leading to retrimming).
When you use a somewhat modern cartridge, turn necks onto shoulders, use tight chambers and little body sizing from rational pressure loads, you won't ever see donut formation. Those are the choices and we make them.

I could make a 6dasher last forever without donuts.
But I could not do this with a 270Win.
Again, a choice.

 

[dkhunt14]

Whenever you run brass into a die size it, brass has to flow forward. The more you size it the more it flows. Other factors are also involved like shoulder angle and how well you turned them and probably how hot you shoot them. Maybe even brands of brass. I like what ZfastMalibu and some of the other guys say about this. Matt

 

[Old Navy]

Ok fellas I have to ask this. Like most everyone here with alot of loading experience I have delt with a Donut issue on brass in the Neck Shoulder junction. My first recollection was with 115 Bergers and JLK's in the 6SLR, seated with the Bullet Boat Tail /Shank (pressure ring) just a nats butt forward of above mentioned neck location. So I have been there and fully understand A. What it is. B. How it forms. And C. how to fix and avoid it.
What Im having a hard time with is that now for some reason EVERY Swinging richard seems compelled to imediatly blert out that....OMG you HAVE to stay ahead of that trouble point for EVERY cartridge we shoot. No matter if its a 308, 6mm Remington, 6BR, 6.5X47Lapua,260, 30'06, 7RSAUM, 300 WSM or what ever the case may be.
Sure we get some brass flow that is pretty Natural. But do we really really see it in some of these case we shoot or is it one of these things where it happens to one guy with some credability so everyone else jumps on the band wagon without actually experierancing the issue and by god its gospel now.
Is the sky really falling? Can you actually reload and shoot with out developing a donut?
I guess I dont see a donut in the 308 or 6BR and just have to ask..Not trying to be snyde by any means. We have such a wonderful cross section of seroius shooters here i thought I would ask.
Thanks for your time.
RussT

Russ, your last paragraph says it all. I am up near 2500 rounds on my current 6BRX barrel. No turn .272" and Lupua brass. No donut I can detect. I use a Redding full length bushing die and never crowd the shoulder. Later! Frank

 

[Alex Wheeler]

I guess it comes down to your accuracy requirement. If I'm shooting 5s at 1k, I will want 4s, then 3s, and so on. Thats the game for me. I am never satisfied with the size of my groups. So until I am breaking world records I have a problem on my targets. So looks like I will have this problem for life! ;D

 

[BradY]

You and I both- check the daily bulletin, Im now looking for sub 2 inches for 5 shots at 1k here in aus....

 

[Alex Wheeler]

Ya, its getting ridiculous. ;D

 

[Rtheurer]

really kinda looking for experience in the "does it happen to ALL cartridges" and not so much as how to control it and what its affects are as that has pretty well been hashed out a hundred times here. I guess what I really am asking is are you seeing donut development in every cartridge that you shoot or is just a case where we may be running some higher pressures to reach the higher node as most of us do here.
Dan Im kinda getting the same feeling is that when we really step on the accelarator, we get faster or more brassflow forward creating this issue. If you run lower normal pressures it may NEVER develop in the life cycle of your brass. Is this what everyone else is seeing or is just me? If it is what everyone else is seeing then the blanket statment of donut issue on every cartridge of every design is wrong.
Lower chamber pressure means possably no donut? 243 shoulder vs a 40* shoulder does that make a difrence?
Might have to get out my pin gage set and start tracking this a little more closely.
Good discusion here and I appreciate everyone opinion from the broad spectum of precision shooting.

 

[amlevin]

Donut? What donut? The pilot on my case trimmer has a cutting notch on the end that merely cuts out any donut that's in it's way. It's an RCBS. Haven't had a "donut issue" for several years now (other than the one that forms over my belt in winter months )

 

[Alex Wheeler]

I have only noticed the donut in cases that I have necked up..

 

[mikecr]

does it happen to ALL cartridges?

This is an unqualified(open) question. Does anything happen to all cartridges?
NO

There is a potential donut present in new cases, which is inherent to their manufacture.
You can measure it with a neck mic. If you don't remove it, and you FL size necks, you bring it into play.
And the ways donuts come back, even if you had initially removed them, has been covered.
The answer is still NO

 

[marwitz89]

I guess it comes down to your accuracy requirement. If I'm shooting 5s at 1k, I will want 4s, then 3s, and so on. Thats the game for me. I am never satisfied with the size of my groups. So until I am breaking world records I have a problem on my targets. So looks like I will have this problem for life! ;D

Sounds exactly like me!!!!! Always striving for something better. I think that's part of the fun though..

 

[6BRinNZ]

Personally I don't see the big deal in people pointing it out. IMO as a principle its a good idea to stay away from the neck should junction.

Very little is gospel in reloading but I think there are some principles that are a good starting point.

For instance - don't load into the neck shoulder junction and don't believe everything you read on the internet...follow the later and you will most likely be fine.