6XC-how to remove donuts (I hate to even bring it up but need some help)

[Michael C]

I bought a used 6XC target rifle (prone rifle) and it came with a bunch of fired brass from that chamber. The prior owner had turned the brass, but, I don't think he got it enough to the shoulder to prevent the donut. I had not noticed them at first and loaded them to his recipe and had some trouble on a couple not chambering (with firing pin removed) and measured the necks of those and found they are quite enlarged.
I have the neck turning tools that I just got from Sinclair but have never turned necks. I also have an inside neck reamer that I hit one case with to see if it will do the job... and it did. However, I want advice as to the best approach. Turn down to the shoulder area as I have read about here, or just hit with the reamer? The rifle shoots very well with the load I was given, no pressure issues, but, the chamber is tight necked (when I rebarrel it will have a no-turn neck).
If I should turn the necks do I size first, or expand and turn then size?
Mike

 

[mikecr]

Turning doesn't really remove donuts, as there is no way to get all of a thicker area to the outside(due to spring back). But turning is effective to mitigate thicker shoulder brass from becoming donuts in the neck on fire forming.
Once the brass is fired it isn't easy to get it back to new dimensions, where turning works best.
So for fired brass with a 'donut problem', you have reaming, and/or not seating bullet bearing into donut area, and/or partial neck sizing with or without pre-expansion(depending on 'problem').
I don't like the reaming option, and would replace the brass before I went there.

 

[John Russell]

[...] I also have an inside neck reamer that I hit one case with to see if it will do the job... and it did.

Mike

If the inside reamer did the job, then do it and get on with the fun part of it.

 

[jlow]

I bought a used 6XC target rifle (prone rifle) and it came with a bunch of fired brass from that chamber. The prior owner had turned the brass, but, I don't think he got it enough to the shoulder to prevent the donut. I had not noticed them at first and loaded them to his recipe and had some trouble on a couple not chambering (with firing pin removed) and measured the necks of those and found they are quite enlarged.
I have the neck turning tools that I just got from Sinclair but have never turned necks. I also have an inside neck reamer that I hit one case with to see if it will do the job... and it did. However, I want advice as to the best approach. Turn down to the shoulder area as I have read about here, or just hit with the reamer? The rifle shoots very well with the load I was given, no pressure issues, but, the chamber is tight necked (when I rebarrel it will have a no-turn neck).
If I should turn the necks do I size first, or expand and turn then size?
Mike

Kind of interested in finding out more about what you mean by not clambering and what you mean by the necks being enlarged?

 

[jr600yd]

Everyone has a different approach to this problem. I had the same problem after fireforming 22/250 Lapua brass to 6XC. This is my solution. FL size the brass. Run necks over an expander mandrel. Turn necks to desired thickness and run cutter into shoulder about 1/8". This works for me.

 

[jlow]

If the inside reamer did the job, then do it and get on with the fun part of it.

The problem with the inside reamer (as Matt will tell you) is it scratch the inside of the neck and that can affect "neck tension" and all the consequences..... When the OP said "it will do the job...", sure it will remove the donut, but.....

 

[dkhunt14]

Kind of interested in finding out more about what you mean by not clambering and what you mean by the necks being enlarged?

I would also watch to know what you mean by this. Is the bullet pushing the brass out there or is the die not sizing this area? Are you using anow expander button or Mandrel? Do you feel the bullet going easy and then hitting the donut when seating them? Matt

 

[Michael C]

I seat the bullets (105) below the neck as that is apparently how the chamber is cut and I don't like to jam. When I seat I can feel the bullet come up against the donut. I some of the donuts are severe enough that they are being pushed out by the seating operation as the bullets pass by them, thus push brass outward and cannot chamber.

 

[MrMajestic]

Lengthen your throat as to keep the bullet of your choice out of the doughnut region.

 

[tenring]

Exactly correct - have your smith run a throating reamer in just a tad - enuf to keep the bullet above the donut.

 

[savagedasher]

Any time you shoot depending on the neck angle your going to get donuts like others said seat the bullet foward . The difference in shoulder angle makes a big difference.
Larry

 

[mikecr]

Any time you shoot depending on the neck angle your going to get donuts

Not sure where you're coming from here.
With a plan, the donut issue can be mitigated from the beginning, and never returning.
With another plan, donuts can be worked around as to remove from 'problem' status.
With a bad plan(as is the case here), existing dounts are left or further caused, and brought into problem status.
There are always choices, and that's what they are.

 

[savagedasher]

Not sure where you're coming from here.
With a plan, the donut issue can be mitigated from the beginning, and never returning.
With another plan, donuts can be worked around as to remove from 'problem' status.
With a bad plan(as is the case here), existing dounts are left or further caused, and brought into problem status.
There are always choices, and that's what they are.

Change the throat to where you seat the bullet foward of them . Change the shoulder angle of the gun to where you don't have as much movement . Larry

 

[bsumoba]

IMO, bushing dies create a lot of the donut problem. even if you turn necks or inside neck ream, using a bushing die seems to make them come back unfortunately.

when I do inside neck ream the donuts out, I use a brush with 0000 steel embedded in the bristles and run that into the neck to smooth it out.

 

[DTubb]

The 6XC was designed so as to never need to seat the full diameter at the base of the bullet (not including the boat tail) past the neck shoulder junction and still keep the OAL of the loaded round to around 2.75" when loaded with the heaviest weight bullets.

This then allows the user to continue to follow the lands as the barrel wears an still allows nonbinding feeding out of a 2.875 Knight magazine box.
So a 2.850" oal will easily feed out of the box.

Also if your fired piece of 6XC brass will not let the bullet you are currently shooting drop freely into the fired case then your 6XC chamber's neck is too tight.
Dtubb

 

[mikecr]

IMO, bushing dies create a lot of the donut problem. even if you turn necks or inside neck ream, using a bushing die seems to make them come back unfortunately.

All I use are bushing dies, most of my chambers are tight neck, no donut creation.
Donuts are inherent to brass manufacture. Once removed, they come back only from thicker shoulder brass moved into necks.
Typically, this is from necking up in forming, or heavily FL sizing low shoulder angle and higher body taper cases. Brass is rolled thicker toward thin.

The 6XC has a 30deg shoulder which does not contribute much in the way of brass movement with rational FL sizing. The origin of OP's brass has yet to come out.
Was it 6XC, or formed from 243, 22-250, 260?

 

[bsumoba]

All I use are bushing dies, most of my chambers are tight neck, no donut creation.
Donuts are inherent to brass manufacture. Once removed, they come back only from thicker shoulder brass moved into necks.
Typically, this is from necking up in forming, or heavily FL sizing low shoulder angle and higher body taper cases. Brass is rolled thicker toward thin.

The 6XC has a 30deg shoulder which does not contribute much in the way of brass movement with rational FL sizing. The origin of OP's brass has yet to come out.
Was it 6XC, or formed from 243, 22-250, 260?

tight neck chambers will help because the bushing doesn't have to size down the neck nearly as much. if you run a lot of neck clearance and use bushing dies, when you size brass down, the bushing doesn't go to the bottom and all that material in my experience gets pushed down to the neck/shoulder junction.

I had turned brass that after a couple firings, created a donut. so, the neck turning into the shoulder did not mitigate the donut issue. I inside reamed them out and after 2 firings, came back. I run a .317 neck and my loaded round neck is .312-.313.

I normally do not care about donuts because I load above the donut, but I had one barrel that liked it seated down a bit further and went into the donut region.

 

[highlife]

Is there anybody that offer inside neck reaming service ?

 

[noload]

If I suspect any cases with donuts, I Check them with a hand reamer .243, .284 etc. before sizing. Sometimes I cut a very little, sometimes not, but at least I know.

 

[Michael C]

My brass is Norma 6XC only fired in this chamber. However, the chamber seems a little odd as it has a very short throat.