Neck-Turning - What order to do?

[longrangehunterII]

I've lately be necking down Lapua 308 Winchester brass to form 7mm-08 remington, and now seem to have a tight neck situation due to the extra brass increasing the thickness of the neck.

The 7mm-08 Federal and Winchester brass I've used in the past of a loaded round tends to measure around .3110", but the neck sized down Lapua brass of a loaded round measures .3150"-.3155". Which according to SAAMI is at the case neck dimensions of the case (.3150"), the chamber dimension is .3170" at the neck shoulder juncture and .3160" at the end of the chamber. Which in this case is rather tight for neck expansion to release the bullet upon firing. These loads with unturned brass have also not produced the same bug holes as the previous loads with the other brass leaving me to think I'll need to turn down the necks.

Wow..... I would never like to neck turn another piece of brass in my life again! Pain in the butt, sore palm as well from holding onto the case holder tightening and doing the neck turning its self.

My thoughts:

Neck up if at all possible. No need to neck turn since the brass neck will thin during the process.

If you neck down, I hope you have a factory chamber and not something cut like a match chamber or you might be doing a ton of work for very little gain. I found the best way with the end result being better is to turn the case first, then neck down. Or make it even easier on yourself and just inside neck ream the darn case.

Here's why:

The factory new parent case will have perfect parallel sides on the neck after running it over the mandrel. Which will prevent any excess brass from being removed that is not fully sized in the die at the neck shoulder juncture if you've already sized down.

If by chance the case as been already fire formed, then turning after will also produce a more concentric neck then if it wasn't fire form first.

I use at least a 6x magnifying glass to check the progress of the neck turning. If you turn a new unfired unsized parent case and turn the neck "to" the shoulder, you'll see that after sizing down the turned portion will become part of the new neck formed, and it will look uniform. vs. if you turn a neck down case, you will need to cut just to the point that the cutter puts a beveled edge on the shoulder. But here the deal, you'll notice when the cutter is 4/5 of the way down the neck it will start to remove more material with each turn then the rest of the neck or if done on a factory parent case or a fire formed case. That's because during the necking down in the sizing die the brass has moved to not only make the neck thicker but more brass moved into the neck shoulder juncture that the sizing die made... the "dreaded donut" and/or a false shoulder will appear. Which is why you'll need to neck turn all the way to the neck shoulder juncture. You'll also need to resize again after turning the neck, where the sizing button will iron out the donut to the out side of the neck. Which you'll avoid doing that twice if you neck turn the parent case first, or a neck reamer can be used to remove the donut/and or the neck thickness of the parent case in the first place if you'd like to forgo the neck turning altogether!

Either way avoid the hassle and buy properly head stamped brass and enjoy all that extra time shooting, hunting or watching TV for that matter. Me I still have 325 pieces of brass to do...... so I bought myself some nice gloves with blister armor in the palm so I can maybe actually finish this job I wish I didn't have to do!

 

[Pdvdh]

Wow..... I would never like to neck turn another piece of brass in my life again! Pain in the butt, sore palm as well from holding onto the case holder tightening and doing the neck turning its self.

Me I still have 325 pieces of brass to do...... so I bought myself some nice gloves with blister armor in the palm so I can maybe actually finish this job I wish I didn't have to do!

Are you not be using a battery powered drill to turn the brass for the outside neck turning?

Which brand outside neck turning tool are you using?

 

[longrangehunterII]

Are you not be using a battery powered drill to turn the brass for the outside neck turning?

Which brand outside neck turning tool are you using?

No I'm not, turning them all by hand using a K&M Neck Turner Kit. At first I was using Imperial Dry Neck Lube inside the necks, well it wasn't enough to handle the friction, so I which to using Imperial sizing die wax instead and the issues went away making my life much easier!

The real issue was locking the case into the case holder that caused a lot of the pain in my right hand (the one I use to hold the case holder in). I now use a wrench, which helps. Most of this is just a learning curve...... but I'm not a fan of turning necks either way, but in this case I had to.

 

[Pdvdh]

Yikes! I use K&M neck turning tools, but I use a battery powered drill. You can purchase tool attachments that will hold the cartridge case head securely. Then chuck the tool into the drill and turn away. Let the battery powered drill do the turning. It's not a terrible chore at all then. Plus you'll get a better end product. You're needlessly suffering self-abuse.

Imperial Case Wax is a pretty good lube for inside case necks and the neck turning mandrels. I use it also.

 

[TracySes23]

To do it properly on fired brass: first, you need to reduce the neck size by sizing. Then open the necks up with an expander. Virgin cases need to be opened with the expander first.

Expand necks to all be the same diameter before you begin turning.

They also need to be the correct inside diameter of the neck so as to fit the spindle it's going to fit on properly.

Spencer

 

[jrock]

i think it would be a good time for somebody to start a threat on how well there groups are before this and just how much better there group sizes are after this
skim coat neck turning .

I neck turned my .243 in a factory rifle and it consistently shrank groups about 0.2" or so depending on the bullet. One bullet I couldn't get to group under 1.25" until I neck turned the cases. I shoot Winchester brass. I did it to have more even neck tension.

 

[FearNoWind]

The most direct answer to "why are you neck turning all your brass in the 1st place" might be to achieve uniform neck wall thickness. With that as the objective, it really doesn't matter whether you first "fire form" the necks or turn new brass. .001 is 001 on a new case or fired case; the case doesn't know when it was removed and once the uniform neck wall thickness is achieved the next objective would be to establish a desirable overall neck tension on the bullet.
I typically turn necks by determining where the thickest part of the neck is, using that as a zero point, and turning until the neck wall is uniform. Then I fire the case. (I see no reason to use a weak load/cream of wheat concoction. I just get a little trigger time having fun punching holes in targets)
Next I slightly resize the case (so that it is just under neck expander dimensions) and run the neck expander through it to round everything out. The fired case tells me (within reason) what the chamber looks like; the wall thickness consistency tells me that if I turn off any more of the neck it will remain consistent overall; so all I have to do is a little math to come up with neck wall to chamber wall clearance and neck tension and select a neck resizing bushing to meet my needs.
I think it's always a good idea to remain mindful that working the brass tends to harden it so an annealing schedule can help a lot to lengthen brass useful life.

 

[TracySes23]

I turn new necks, up onto shoulders, to head-off donuts.
If you fireform first, you've missed this donut addressing, and you might struggle to get full length of necks sized and expanded for good turning mandrel fit.

New brass is ready for expansion and perfect fit, right out of the box.
Now if you're forming a new cartridge, things need to be planned out & may change.

Mike,

I'm curious as to why you mention the possibility of donuts from fire forming before you turns the necks, unless you're referring to wildcat cartridges.
A few months ago, I purchased some Remington 22-250 brass. Some of is so bad when I neck turn it the angle portion of the cutter cuts on one side of the shoulder, a good 4-5 thousands before it will cut any other portion of the shoulder.
I feel like I may have ruined approx. 40 rounds because of this. I made a precision sub-collet with a step in the ID in order to rotate the brass in my Hardinge lathe & the neck OD on half of them ran out as much as 30-35 thousands TIR. I finally decided to fire form the remainder so the cartridge will be filled out & perpendicular to the base. I can't see how it's possible for a donut to form on factory brass in a factory chamber. This should insure when the cutter reaches the shoulder area, it will cut more concentric to the shoulder.
I also recently purchased 100 rounds of Lapua brass in the same caliber & after checking them, they run much truer (.002"-.015", although I haven't turned any of them yet.

Please enlighten me.

Spencer

 

[Pdvdh]

Mike,

I'm curious as to why you mention the possibility of donuts from fire forming before you turns the necks, unless you're referring to wildcat cartridges.

Please enlighten me.

Spencer

I'd like to hear more from Mike also. I remember reading his post the first time, and I presumed this was a reference to wildcat cartridges, where the shoulder is blown forward out into what would have originally been part of the neck on the parent cartridge.

But I can't think of any reason not to outside neck turn on new brass on factory cartridges, unless its so non-concentric that you encounter the issues you had. I full length size new cases in standard factory cartridges and then insert the neck expanding mandrel into the re-sized virgin case neck to prepare the inner case neck ID for outside turning on my K&M neck turning tool.

I especially like to outside neck turn prior to fire forming wildcats because I don't need to turn up into the shoulder prior to fire forming. Just turn the necks up to the edge of the shoulder. After fire forming, a portion of the turned neck on the parent case is then shifted back into the shoulder of the fire formed wildcat case, preventing future donut formation.

 

[TracySes23]

I'd like to hear more from Mike also.

There are a number of people on this site who are very experienced & knowledgeable. Mike is one I have a lot of respect for. Usually I much prefer to ask a question which will get me some clarifying info without offending or burning a bridge to a flow of good info.

If I want to say something that might be a correction of something posted. I'll sometimes send a PM instead, so it'll keep either of us from looking bad.

I've learned to edit my responses as much as 4-5 times before I see all the typos or ignorant statements. We're all ignorant about something.

 

[Mikecr]

Until turned all necks hold increased thickness near the neck-shoulder junction (compared to case mouth or mid-neck thickness). This is inherent to brass manufacture. Whether or not it comes into play depends on your reloading plan and actions. For instance, if you FL size unturned necks, you have donuts, and if you seat bullet bearing near this, your accuracy probably isn't as good as it could be. Constant annealing may seem to 'fix' this and other bad plans. In forming a wildcat you can amplify or reduce this (all part of the plan and management). I imagine a big number of reloaders are now using bushing dies, which partial neck size, allowing inherent donuts to remain beyond interference even while seating deep enough for magazine fit.
Brass moves with body sizing upward, thick towards thin. Even if you begin without donut issue, when you body size, you're moving brass thickness upwards toward case mouths(where you trim some of it away). The neck-shoulder junction is getting thicker too. This is apparently part of many peoples plan, and they re-turn, or ream, or maybe ignore it due to short brass life anyway. But there are 4 benefits in outside turning:
1. Managed thickness/bullet grip
2. Managed neck clearance
3. Lower TIR
4. Getting ahead of donuts
Where you can turn a bit onto shoulders, you can address donut formation right from the git-go. Depending on the cartridge & chamber design, you might forever remove donuts from issue. But if you've fireformed the cases beforehand, you lose benefit #4. That's all I mean't there, and it might not matter for you.
Also, new brass just happens to be semi-ready to load. The less manipulation to this, the easier and better your turning. You should plan to simply expand new from the box necks, and turn. There should be no benefit in further sizing(FL or fireforming) for this operation. The fireforming later brings it all together(finishes the operation).

 

[Mikecr]

Oh yeah, another thing; Don't try to re-invent neck turning. It really is so easy a caveman can do it.
When you can't align it, float it.
Turning systems are based on your hand holding and feeding of the cutter onto necks (floating). They're designed with matching components. Use them as designed, and it won't ever matter how much runout there is in the brass. The results will still be excellent.
Don't fireform 1st or FL size to try to make cases wobble less during turning. You'll just complicate what is otherwise -not broken.

 

[woods]

Mike, I've often wondered whether a neck will re-center in alignment with the case body if you turn and it is off-center to begin with because of thick-thin variance

IOW like this pic shows

Will fire forming a turned neck like in the pic move the neck over to back in alignment?

It would be better to have good brass with little neck thickness variance to begin with but if you have a neck with .002" or .003" variance, will turning correct the problem. Or does the thick-thin variance extend into the shoulder-case body and problems will continue with that brass?

 

[Mikecr]

Mike, I've often wondered whether a neck will re-center in alignment with the case body if you turn and it is off-center to begin with because of thick-thin variance

No it won't align anything. Turning only get's thickness to a standard.

Will fire forming a turned neck like in the pic move the neck over to back in alignment?

Yes, somehow fire forming does, turned or not. Brass is and must be fire formed to straight- initially (dies cannot do it).

It would be better to have good brass with little neck thickness variance to begin with but if you have a neck with .002" or .003" variance, will turning correct the problem. Or does the thick-thin variance extend into the shoulder-case body and problems will continue with that brass?

Turning addresses necks only. The case body is another matter that is still affected by thickness variance, because this runs full length of cases.
But again, somehow, fire forming brings cases to straightness regardless of thickness variance - initially.
The only thing that changes this straight condition is sizing(actual yielding). While you never size the case body, and with turned necks, runout does not grow. It's when you run a case forming in a loose SAAMI chamber through a tight SAMMI FL die that you 'release the Kraken' and TIR grows, and continues with each cycle toward a new shape, and cannot ever be fixed because you can't remove the added energy from FL sizing(would take full body annealing and re-FF).