Neck turning angles

[gunsandgunsmithing]

Good question. I haven’t really decided yet which would be the best approach but I think I would like to cut prior to fireforming.

At this point I am under the impression that if I turn necks before fireforming then I can cut into the shoulder a little and remove the thick shoulder material before it becomes a doughnut. This would be a pre-emptive approach to doughnut management. Cutting after fireform would guarantee the formation of a doughnut.

- Trevor

Depends. I've fire formed using the cream of wheat method(except I just use tissue paper). That forms the case but leaves the neck id small, yet large enough to run over an expander mandrel for turning. The doughnut gets pushed to the outside and is turned off when turning the necks. Works very well. Many people prefer this method over all others.

There's certainly more than one way to skin this cat but neck turning is the simplest of machining operations. It does however, require attention to detail to do a very good job.

A few things that cause problems with consistency are the mandrel flexing, the cutter flexing and the cutter body getting hot. Another is too tight of a fit of the case on the mandrel, causing excessive heat and potentially galling of the case neck brass to the mandrel. Too loose is even worse when it comes to consistency.

Part and tool deflection are best dealt with by taking light cuts or doing them in two or more passes. Heat just has to be managed. The cutter assembly getting hot can make a significant difference in the final dimension.

 

[gunsandgunsmithing]

Before K&M developed the inside neck reaming mandrel for their neck turners....

I have an old Forster neck turner and inside neck reamers that are about 50 years old. They've been around a while.

 

[LA50SHOOTER]

I have an old Forster neck turner and inside neck reamers that are about 50 years old. They've been around a while.

Yes, but there primary intended purpose was to thin down the necks of brass after it had been run through forming dies during case making operations where necking down was accomplished, not around addressing the dreaded doughnut.

 

[gunsandgunsmithing]

Yes, but there primary intended purpose was to thin down the necks of brass after it had been run through forming dies during case making operations where necking down was accomplished, not around addressing the dreaded doughnut.

I'd be speculating to say otherwise.

 

[JRS]

The cutter on the old Marquart didn't have much of an angle on it, and worked just fine.

 

[LA50SHOOTER]

I'd be speculating to say otherwise.

Then "Do Tell" My Friend !!

 

[LA50SHOOTER]

The cutter on the old Marquart didn't have much of an angle on it, and worked just fine.

What's Your Point in all of this ?? - That I'm Wrong ?

 

[JRS]

What's Your Point in all of this ?? - That I'm Wrong ?

Not at all. The point is, it worked. As did the Sinclair, Hart, Jackson, Morrison, etc. Each of which came with a standard cutter angle (whatever it was).

 

[LA50SHOOTER]

Not at all. The point is, it worked. As did the Sinclair, Hart, Jackson, Morrison, etc. Each of which came with a standard cutter angle (whatever it was).

Yes - I agree. - My point was in my first reply on this thread that I felt it is correct to use a cutter that has a greater angle than the shoulder of the brass being neck-turned. Now that I've had a bit of time to think about using a cutter angle with the same angle as the brass being neck turned, I believe that it's probably (and I only say this because I've not tried it) okay as well, as long as one doesn't take it too far. I know that using an increased angle cutter if one turns to deep into the shoulder then obviously the neck could end up suffering a casualty during firing if the brass gave way due to an excessively thin spot that was cut into it at the neck / shoulder junction. - I don't claim to be an expert on neck turning, but I can say with honesty that I've turned over 4000 pieces of brass in the last 12 months time and I have several different tools that yield quite good results in neck turning.

Regards, RM

 

[Ledd Slinger]

All I know is that my 21st Century neck turner does an excellent job. Extremely consistent. Better than any other turner I've use previously and I've never had donut issues using the 21st cutters that match the shoulder angle. Obviously a person would not want to cut too far into the shoulder. That's all part of just knowing how to use your tool correctly so you don't comprise the integrity of the brass

 

[RW]

On a different wildact that requires fireforming, I cut down onto the shoulder before fireforming, the again afterwards to hit the shoulder properly.

That is what I have allways done on my ackleys with a 40 degree shoulders using a K&M turner

 

[mikecr]

There are actual reasons for doing things, and why they work or don't work as applied.

The only reason to turn onto shoulders is to mitigate donuts.
That is, reducing shoulder thickness that will be later brought into the neck(through final forming).
There should be no reason to repeat a turn onto shoulders after fire forming.
And where you're not bringing thicker brass into formed necks, there is no need for turning onto shoulders.

Also, this thread is about neck turning angles, which is independent of turning equipment brand.
This is a matter of your local shoulder angles -vs- your particular cutter angles.
So that someone having good results with an example 21st Century turner, means nothing without understanding which of 11 cutter angles offered (by 21st Century) were applied to what local shoulder angles, to reach the described result.

 

[RW]

There are actual reasons for doing things, and why they work or don't work as applied.

The only reason to turn onto shoulders is to mitigate donuts.
That is, reducing shoulder thickness that will be later brought into the neck(through final forming).
There should be no reason to repeat a turn onto shoulders after fire forming.
And where you're not bringing thicker brass into formed necks, there is no need for turning onto shoulders.

Also, this thread is about neck turning angles, which is independent of turning equipment brand.
This is a matter of your local shoulder angles -vs- your particular cutter angles.
So that someone having good results with an example 21st Century turner, means nothing without understanding which of 11 cutter angles offered (by 21st Century) were applied to what local shoulder angles, to reach the described result.

Actualy I was referring to turning the necks prior to fire forming a wild cat or ackley. I don't come back and turn after as I only turn once and the angle of the cutter on the K&M tool has worked for me on wildcat and standard because of the small amount of the cutinto the shoulder. Sorry didn't mean to get off topic. RW

 

[gunsandgunsmithing]

Actualy I was referring to turning the necks prior to fire forming a wild cat or ackley. I don't come back and turn after as I only turn once and the angle of the cutter on the K&M tool has worked for me on wildcat and standard because of the small amount of the cutinto the shoulder. Sorry didn't mean to get off topic. RW

I mentioned this somewhere but, if you turn into the neck/shoulder junction of a parent case to be Ackleyized, you are affecting the headspace.

Not saying that it can't be done, just pointing out this fact.

 

[Ledd Slinger]

I mentioned this somewhere but, if you turn into the neck/shoulder junction of a parent case to be Ackleyized, you are affecting the headspace.

Not saying that it can't be done, just pointing out this fact.

???

FL die bumps the entire shoulder. Not sure I understand how a small cut onto the neck shoulder junction would effect headspace in any way. Additionally, I don't see the significance of worrying about this when a fire-formed case is what a person should use to properly fine tune headspacing on a FL die.

 

[gunsandgunsmithing]

???

FL die bumps the entire shoulder. Not sure I understand how a small cut onto the neck shoulder junction would effect headspace in any way. Additionally, I don't see the significance of worrying about this when a fire-formed case is what a person should use to properly fine tune headspacing on a FL die.

Okay, two things. First is that you're right, with assumptions that the fl die contacts the case at the neck shoulder junction, precisely. Most of us use a bushing die, I think. But, if you cut into the shoulder below where it headspaces, you've moved the point of contact for an AI. What am I missing, here?

Again, back to the AI...they are formed from some parent case. It's not an AI until formed. So, are you turning necks after forming? If not, you're moving the area where the brass is meant to headspace to, in the chamber.

Please explain how I'm looking at this wrong.

 

[mikecr]

If I remember right you initially headspace off neck-shoulder junction in an Ackley chamber(which is cut a bit short for this).
Then turning into that datum could present a problem to work around.
I don't think you'd need a false shoulder, but you could create a FL neck sized shelf and jam bullets for 1st fireforming.

With something like a dasher you can turn to a set length, leaving a turned shelf to HS off for forming.
There is always a way with wildcats. Sometimes they get complicated.
For a 26wssmImp, I had to neck turn at 25cal(new brass)(trial & error), expand to 27cal (for false shoulder), partial size down to 26cal at a length providing correct HS. All of that was fun..

 

[Ledd Slinger]

Hey Guys,
If you watch the Hornady video, 1:06 minutes in, they specifically warn about cutting into the shoulder and how that weakens the case. I wouldn't cut into it. If my cases have donut when I expand the neck cases to the final dimension with a mandrel, that takes care of it. YMMV.

Joe

Yeah because Hornady is the optitomy of precision handloading and ultimate 'go-to' source for accuracy

Hornady techs probably wouldn't even have a clue about what we are talking about here...

 

[gunsandgunsmithing]

Yeah because Hornady is the optitomy of precision handloading and ultimate 'go-to' source for accuracy

Hornady techs probably wouldn't even have a clue about what we are talking about here...

I suspect that you're probably right.

 

[mikecr]

If my cases have donut when I expand the neck cases to the final dimension with a mandrel, that takes care of it.

Yeah provided you have neck clearance for some of the donut thickness on the outside, and don't seat bullet bearing into donut thickness that sprung back to the inside, and don't FL size necks(bringing donut into tension). It works of course,, probably common sense for many.

But here we're talking about taking a cut onto neck-shoulder junction -to mitigate donuts. This works also, and a lot of people do it. I found posted pic that represents what I'm comfortable with(I leave mine like this). This won't postpone donuts for heavily FL sized cases for long. But I don't do that. It does allow for a bit of turned neck-shoulder junction to roll into neck on firing expansion, where it stays with bushing neck sizing. With 2thou of neck clearance a bullet would fall right through the fired neck.