Case neck Donuts

[supercorndogs]

I have some 8 or 9 times fired Lapau 22-250 brass. When running fired brass into my FL, it drags the expander ball on what feels like a very small portion of the neck right above the shoulder junction. Is it possible to get a donut on brass that has never been neck turned? How would I check it? Do I need neck turning stuff to check it?

 

[spife7980]

Pin gauges, drop em in and see what sizes fit into the neck, fit into the neck but stop on the donut, fit in and fall through past the donut.
If they don’t stop on the donut then you don’t have a donut I would worry about.

Or what I would do

 

[Steel head]

Yes
My buddy’s 338 Norma brass has a very prominent donut
Never neck turned but always sized with bushing die.

Doesn’t matter with the long freebore it has.
You can gauge with pin gauges or even feel them with a pick.

 

[supercorndogs]

A bullet will not fit past the donut in a fired case. I don't think I can just ignore it. I would think after sizing it should be pushed to the outside where it could then be turned off. Is that a good course of action?

The rifle is not shooting well with this brass and the 70RDF. I loaded up some 60g bullets in some winchester brass this morning and the rifle shoots fine. I loaded up some 70 RDF in the winchester brass to see they are still all over the place in that brass too. Supposed to be 1 in 9.

 

[Cardboard Assassin]

A bullet will not fit past the donut in a fired case. I don't think I can just ignore it. I would think after sizing it should be pushed to the outside where it could then be turned off. Is that a good course of action?

The rifle is not shooting well with this brass and the 70RDF. I loaded up some 60g bullets in some winchester brass this morning and the rifle shoots fine. I loaded up some 70 RDF in the winchester brass to see they are still all over the place in that brass too. Supposed to be 1 in 9.

Yes, I believe the preferred solution is using a mandrel to push the doughnut to the outside where it can be removed via turning.

 

[spife7980]

The rifle is not shooting well with this brass and the 70RDF. I loaded up some 60g bullets in some winchester brass this morning and the rifle shoots fine. I loaded up some 70 RDF in the winchester brass to see they are still all over the place in that brass too. Supposed to be 1 in 9.

I wasted 500 trying to prove to myself that the 70 rdf would stabilize in a 1/9 twist barrel. They never did. Thats a long skinny bullet, spin em faster. I bet you have the same results in this other winchester brass.
Theyve shot great out of the thee 7 twist barrels Ive tried them in since.

 

[supercorndogs]

In what cartridge or what MV? Whats your elevation?

They are longer than I thought. Quite a bit longer than the 77SMK.

 

[spife7980]

In what cartridge or what MV? Whats your elevation?

They are longer than I thought. Quite a bit longer than the 77SMK.

All 223s at like 700' elevation.
The 9 twist was a 16" so it was on the slower side of the spectrum down in the 2700s which is where I had the "best" luck with them if memory serves correct using varget, its been a few years now. But I have them in a 16" 7 twist pva now and they shot fine just like one would hope they would right around 2800 with 8208 with out any crazy work like I went through unsuccessfully with the 9 twist. And the 7 twist 24" Ive since sold I had them moving around 2900 with varget. And my 7 twist 16" ar they shot well enough for a quick quality check for a 100 dollar barrel with varget before I went to soft tips and themal.
But that 9 twist had me pulling my hair out because I thought "its gotta handle a 70" except its like a needle.

 

[supercorndogs]

I think I will put the old brass on pause for moment and make sure that I can stabilize the bullet. I am at 3500' and the bullet is traveling about 3300fps. Looking at the group in the Winchester brass I think its good, but I saw a one off in the Lapua brass that looked good too. Maybe I will get out out some new Winchester and run another OCW test with the 70RDF and 4166. The group I got from an arbitrary charge was right at an 1.1 moa with the 70g, and the 60s were .75 or a little better. Mind you this not heavy rifle. Around 10lbs. bags and bipod 5 shot groups.

The OCW in the old brass was like reading tea leaves.

 

[supercorndogs]

@spife7980 Was correct, the 1 in 9 is not doing it for the 70g RDF even at 3300fps. I did turn the necks to remove the donuts, I can't say if it changed anything. The 70 RDF are still all over and the 60g Hornady still shooting ok. So I will quit wasting my time with the 70s in my 22-250.

 

[NamibHunter]

“Donuts are a real pain….”

Have moved this to a new thread. Probably a bit off topic for this thread.

Link:

Dealing with donuts

We all know donuts are a real pain to deal with. Have tried to summarize what (little) i know about the topic, and curious to learn what tricks you guys have tried! Detecting donuts: Have recently tried gauge pins to feel for a donut, and it works pretty well. Some cases get donuts earlier...

www.snipershide.com

 

[Newbie2020]

Im looking to go this route w a 223ai. Would 1:8 be sufficient to stabilize both 55s and 80s?

Or do i need to go 1:7?

 

[918v]

Lee collet neck die squishes out the donut

 

[GONE BAD]

Squishes it out to where?
Back into the shoulder or spreads it evenly into the neck?
Do the necks grow in length more than average compared to cases without donuts?

I've dealt with donuts in a 6.5-284 and, (for me) as luck would have it, I had a drill bit that fit the throat of the fired brass and I was able to cut the donut out. Probably redneck but it worked

 

[918v]

Squishes it out to where?
Back into the shoulder or spreads it evenly into the neck?
Do the necks grow in length more than average compared to cases without donuts?

I've dealt with donuts in a 6.5-284 and, (for me) as luck would have it, I had a drill bit that fit the throat of the fired brass and I was able to cut the donut out. Probably redneck but it worked

It squishes it into the neck which in turn gets longer and thicker at the bottom, but it’s a gradual taper thickness not a ring.

 

[GONE BAD]

With my 6.5-284 I don't know for sure but I think it border on a chamber length that was to short. The barrel i just installed I set the headspace longer by .003 longer than the go gage, annealed the brass, loaded it up and got really good results. No donuts and velocity and accuracy are outstanding.
The other barrel also suffered from a carbon ring which in my mind attributed to high pressures causing the donuts.
I don't really know but right now I have lots of 1X fired brass to work with and if it doesn't work out I'll just reset the headspace and go from there