Neck Turning Advice - Cutting Depth

[222Jim]

I'm looking for advice on if there is a maximum or recommended cutting depth, i.e. how much can you remove from a neck in a single pass. This isn't a question about how thin the neck can be; it's a question about how much can (should) you remove at one time.

My situation...........I have Lapua brass with neck thicknesses that range from 0.0141" to 0.0159" (multiple measurements around the neck, i.e. at 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock on multiple cases). I want to trim them to 0.0144", thus I'd be removing 0.0015" from the thickest portions of the thickest necks.

So, is it okay to set my neck trimmer (Century XXI Neck Turning Lathe) to get to 0.0144", or it is better or recommended to get this "off" in two or three increments of, for example, a maximum of 0.0010" at a time?

Appreciate your thoughts.

 

[ELR LVR]

I'm looking for advice on if there is a maximum or recommended cutting depth, i.e. how much can you remove from a neck in a single pass. This isn't a question about how thin the neck can be; it's a question about how much can (should) you remove at one time.

My situation...........I have Lapua brass with neck thicknesses that range from 0.0141" to 0.0159" (multiple measurements around the neck, i.e. at 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock on multiple cases). I want to trim them to 0.0144", thus I'd be removing 0.0015" from the thickest portions of the thickest necks.

So, is it okay to set my neck trimmer (Century XXI Neck Turning Lathe) to get to 0.0144", or it is better or recommended to get this "off" in two or three increments of, for example, a maximum of 0.0010" at a time?

Appreciate your thoughts.

If your thinnest measurement is 0.0141
Why don't you turn them all down to 0.0141? or even .014"
As opposed to 0.0144 still leaving a thicker portion on the neck?
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And yes you can take that much off in one pass
When turning necks I approach it the same as Machining anything
Your last pass, take a ghost past to clean up
Your ghost pass will still remove material
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So adjust accordingly so that your last clean up pass allows you to reach your target measurement

 

[222Jim]

If your thinnest measurement is 0.0141
Why don't you turn them all down to 0.0141? or even .014"
As opposed to 0.0144 still leaving a thicker portion on the neck?
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Fair question.

Only 3 out of 100 cases are less that 0.0144, so I "cull" the thinner ones for use calibrating my AMP Annealer (which destroys the case), or as sacrificial cases for any other purpose.

 

[ELR LVR]

Fair question.

Only 3 out of 100 cases are less that 0.0144, so I "cull" the thinner ones for use calibrating my AMP Annealer (which destroys the case), or as sacrificial cases for any other purpose.

Gotcha, makes sense

 

[Straightshooter1]

I'm looking for advice on if there is a maximum or recommended cutting depth, i.e. how much can you remove from a neck in a single pass. This isn't a question about how thin the neck can be; it's a question about how much can (should) you remove at one time.

My situation...........I have Lapua brass with neck thicknesses that range from 0.0141" to 0.0159" (multiple measurements around the neck, i.e. at 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock on multiple cases). I want to trim them to 0.0144", thus I'd be removing 0.0015" from the thickest portions of the thickest necks.

So, is it okay to set my neck trimmer (Century XXI Neck Turning Lathe) to get to 0.0144", or it is better or recommended to get this "off" in two or three increments of, for example, a maximum of 0.0010" at a time?

Appreciate your thoughts.

That's pretty much the range of thickness I found in my Lapua brass. I use a hand held Sinclair neck turning tool and when I turned the necks, I turned them down to .014" in one cut. I simply made sure I didn't try to feed the necks into the cutter too fast using a cordless drill spinning at ~700 rpm. All the brass turned out quite nice and upon measuring the thickness, neck thickness were consistent at .014. IMHO, I wouldn't take more than .002 at a time. For smaller thinner necks, I would go less than .002 at a time. . . like for 6mm necks that are like at .012".

 

[ELR LVR]

That's pretty much the range of thickness I found in my Lapua brass. I use a hand held Sinclair neck turning tool and when I turned the necks, I turned them down to .014" in one cut. I simply made sure I didn't try to feed the necks into the cutter too fast using a cordless drill spinning at ~700 rpm. All the brass turned out quite nice and upon measuring the thickness, neck thickness were consistent at .014. IMHO, I wouldn't take more than .002 at a time. For smaller thinner necks, I would go .002 at a time. . . like for 6mm necks that are like at .012".

I've never taken more than .002" turning necks... usually just enough to make them all uniform
But I would tend to agree here
.002 would be the thickest cut I would take at a time with these small tools
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Heck even in my 13x40 GH I never take more than .010" at a time
I can, but I dont'... I like to preserve my tools so they last as long as possible

 

[BoydAllen]

I'm looking for advice on if there is a maximum or recommended cutting depth, i.e. how much can you remove from a neck in a single pass. This isn't a question about how thin the neck can be; it's a question about how much can (should) you remove at one time.

My situation...........I have Lapua brass with neck thicknesses that range from 0.0141" to 0.0159" (multiple measurements around the neck, i.e. at 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock on multiple cases). I want to trim them to 0.0144", thus I'd be removing 0.0015" from the thickest portions of the thickest necks.

So, is it okay to set my neck trimmer (Century XXI Neck Turning Lathe) to get to 0.0144", or it is better or recommended to get this "off" in two or three increments of, for example, a maximum of 0.0010" at a time?

Appreciate your thoughts.

No problem. I have taken off a LOT more with a single pass with no issues. Years ago, I came up with a way to try things out, without risking expensive brass. I have a collection of brass that was left at the range that I expand up and test turning tool settings and methods with. One thing that I should mention about this method is that sometimes a setting arrived at with one brand of brass, does not produce the exact same thickness as it will when turning another. For this reason I leave the setting a couple of ten thousandths fat and do the final adjustment on the actual cases that I am setting up for.

 

[JFrank]

I turn them to 0.0108 with one slow pass.

 

[Tangent]

I've got a Sinclair Ultimate trimmer. I presume I can use that for neck turning too? I may give it a go with some .308 Palma cases at some point.

 

[RustyInBend]

My thoughts?
Friends don't let friends do neck-turning.
End of thoughts.

 

[ELR LVR]

My thoughts?
Friends don't let friends do neck-turning.
End of thoughts.

I enjoy playing with my Forster's and all the little pilots and such
(It's really got me wanting to use a cute little watchmakers lathe for all this stuff)
One day................

 

[HTSmith]

One thing that I should mention about this method is that sometimes a setting arrived at with one brand of brass, does not produce the exact same thickness as it will when turning another. For this reason I leave the setting a couple of ten thousandths fat and do the final adjustment on the actual cases that I am setting up for.

Big Amen on this. When I changed from Lapua to Alpha there was a significant difference.

 

[222Jim]

My thoughts?
Friends don't let friends do neck-turning.
End of thoughts.

Yes, neck turning is one of those topics, like politics and religion, that sometimes shouldn't be discussed among friends. I'll confess that I'm not 100% convinced it's the answer to any precision issues. But, using neck turned brass, I'm consistently under a 0.25 inch mean radius (20 shot groups at 100 meters), and have a bit of an "if it works, don't fix it" attitude.

One day I'll get brave and try to settle this for myself with a side-by-side trial (same brand, batch & lot) of bullets, primers, and powder, just one set neck turned and the other "raw as received" cases.

 

[LCazador]

I use a Nielson Pumkin' turner so I have the option to turn in .0001" increments. I don't recommend turning more than .0015" at a time. Like mentioned above I do a ghost cut of .0003"-.0005" for a final finish. That final cut can change due to neck tension requirements. In my opinion it's best to neck turn a few, fireform and test before doing the whole batch. Understand that every time you change lots or brands it will change.

 

[60723]

Using the thinnest necks to set your annealer might not be ideal. My setting varies a few numbers by neck thickness.

 

[Cloudrepair]

Yes, neck turning is one of those topics, like politics and religion, that sometimes shouldn't be discussed among friends. I'll confess that I'm not 100% convinced it's the answer to any precision issues. But, using neck turned brass, I'm consistently under a 0.25 inch mean radius (20 shot groups at 100 meters), and have a bit of an "if it works, don't fix it" attitude.

One day I'll get brave and try to settle this for myself with a side-by-side trial (same brand, batch & lot) of bullets, primers, and powder, just one set neck turned and the other "raw as received" cases.

It seems in this case to get meaningful results you would need two reamers . You know a no turn reamer like a 6mm bra 272 neck and a 6mm bra 268 neck made by same manufacturer to same dimensions other than the neck. And then ream the same barrel as close as possible to the previous chamber. like ream the turn test then ream the no turn and test. just cleaning up the neck.

 

[ELR LVR]

It seems in this case to get meaningful results you would need two reamers . You know a no turn reamer like a 6mm bra 272 neck and a 6mm bra 268 neck made by same manufacturer to same dimensions other than the neck. And then ream the same barrel as close as possible to the previous chamber. like ream the turn test then ream the no turn and test. just cleaning up the neck.

This would actually be a very interesting experiment

 

[Ruger15151]

On a another note regarding turning .....

I turn my brass on an AutoDod (cuts inside and outside) and load with an AMP press. My non-turned brass graphs are very consistent. A loading session of 100 rounds creates one solid line. However, the graphs when loading Lapua turned neck brass show much more erratic graphs than non-turned Lapua brass.

Has anyone noticed this?

 

[DaveTooley]

Regardless of the depth of cut consistent feed rate and temperature of the turner itself are important. An aluminum bodied turner will change the depth of cut just from the heat from your hand.

 

[newbieshooter]

It seems in this case to get meaningful results you would need two reamers . You know a no turn reamer like a 6mm bra 272 neck and a 6mm bra 268 neck made by same manufacturer to same dimensions other than the neck. And then ream the same barrel as close as possible to the previous chamber. like ream the turn test then ream the no turn and test. just cleaning up the neck.

This would actually be a very interesting experiment

some other references:

To Turn Necks or Not ?

During my time with the 6 PPC, I shot .261, .262, .263, and .268 necks. With the Dasher and 6 BRA, I have shot .268, .269, and .271 (no turn). What is ideal for the 6mm Cartridges? Well, personal preference has a lot to do with it, but I prefer the .268 for PPC and 6 BR-based cartridges using...

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Most common turn neck diameter for 6ppc?

What is the most common neck diameter for a TURN neck chamber in ppc? 6 ppc. I understand ther is a no turn. But for turning necks, what is the most widely used? .268? Reason I ask this is because It seems to me if there's a holy Grail diameter in neck turning in ppc It should work for Br,Bra...

forum.accurateshooter.com

6 br neck turning question

Sorry guys I'm new to this neck turning gig. I got K&M neck Turner like many suggested. So my 6 br chamber measures .272 on fired brass. What would be a good size to turn my neck to for consistency ?

forum.accurateshooter.com