Neck turning question

[savageshooter86]

when slightly turning into shoulder the cut is not even. It is correct cutter angle

What do I do to correct this?

One side looks perfect, the other barely cuts into shoulder.

Thanks for any tips

This is using 21st century power model lathe

 

[liljoe]

The neck is not straight with the body.
This usually happens in the necking up process.
Joe

 

[savageshooter86]

This is Lapua Palma Brass

Nothing cheap in my reloading process

 

[bigbulls]

I have found this with some new Norma brass also. I just turn it to where I have the cutter set and call it good.

 

[Toejoe12]

when slightly turning into shoulder the cut is not even. It is correct cutter angle

What do I do to correct this?

One side looks perfect, the other barely cuts into shoulder.

Thanks for any tips

This is using 21st century power model lathe

Did you trim them all to same length with a quality trimmer before you turned them? Even Lapua will have some inconsistencies in OAL of the brass right out of the box. Trimming to same length will also square up the mouth of the neck. If the opening is not perfectly square you will get the result you're describing on the neck/shoulder junction with the angled cutter 21st uses. If you don't want the extra step, it's only a cosmetic issue. Doesn't hurt performance at all. I had the same issue last year. Ran all my turned brass over my concentricity gauge measuring both neck and shoulder to check alignment. 99% were good which lead me to the above described and found my issue. Hope it turns out to be the same for you. If not don't sweat it, not hurting a thing.

Edit......This is assuming you have your neck arbor set in your turner where your brass neck bottoms against the base so you end your cut at the same point from piece to piece

 

[Ledd Slinger]

This is Lapua Palma Brass

Nothing cheap in my reloading process

Then I would recommend calling Lapua or the vendor you purchased them from for a replacement or refund. You paid good money for that brass and it should be right.

I also use the 21st Century turning tool and expanders. Machining doesn't get any better than the tools John makes. Highly doubt its any fault of the cutter. Gotta be the brass.

 

[alinwa]

#1, if you're folding, spindling or mutilating the brass in any way, necking up or necking down unsupported, the brass CANNOT STAY STRAIGHT! It's physically impossible.

#2, brass right out of the box, ALL BRASS right out of the box is crookeder than Jewell's teeth. It HAS TO BE, there has been no attempt made to "straighten it." And the idea that some brands are straight and some aren't..... or that some will neck up concentric and some won't.... is just silly. You can't neck brass UP concentric no matter who you are and necking DOWN even fairly concentric requires special tooling. Necking up with shotgun powder makes it fairly concentric, within a thou or two....


Brass straight off the assembly line isn't fit to be "trimmed" or "turned" or otherwise modified more than a few thou.

That's why we fireform.

You want to have a straight cut on the shoulder? Blow the cases out first with shotgun powder.....make a straight concentric shoulder.

 

[Ledd Slinger]

I'm confused about where the idea that the OP is necking his brass up or down came from???

The beauty of the 21st Century neck turning lathe is you can't screw it up. The shell holder and neck turner both float in alignment with each other

 

[alinwa]

I'm confused about where the idea that the OP is necking his brass up or down came from???

The beauty of the 21st Century neck turning lathe is you can't screw it up. The shell holder and neck turner both float in alignment with each other

Go watch the video on the 21st Century site...... right where the guy says "you'll notice" as in "you'll notice the head swivels"...... as he hits the shoulder on the second case, it's got a HUGE swerve into the shoulder.....it winks at you in the video.

 

[spclark]

when slightly turning into shoulder the cut is not even. It is correct cutter angle.

OP’s saying he’s seeing inconsistent depth of cut in the shoulders of his cases.

I’ve seen this too when I skim-turn new Lapua Palma brass, why I prefer to first-turn cases that have been fired at least once before neck-turning.

Hard enough as it is to make cases we’d accept for the price we’re willing to pay, I suppose manufacturers accept that it’s just not worth it to make shoulders as symmetrical as they can case necks and bodies.

 

[Ledd Slinger]

I always like to fire-form before turning necks as well, but some of my tight neck chambers wont allow it. Brand new cases have to be turned or the rounds wont chamber. No other way around it. We pay good money to get quality brass from Lapua, they should make it right.

 

[Richard Coody]

before you start complaining about the brass check the necks for concentricity then you will know if it is your turning equipment/procedure or the brass. i have never had such a problem with my pma model a and lapua brass. of course i use cutter angles that match the shoulder angle.

no doubt fireforming will straighten out those necks.

i turn new brass lightly. then after fireforming, sizing and trimming i turn again.

 

[savageshooter86]

There’s no issue I don’t think. Never said I was worried. As others stated I think it’s just cosmetic. But was just noticing it as I turned my cases.

The reason to cut slightly into it is to help prevent the donuts forming. But my Bullets so far out anyway I never had issue with donuts

I’ll try trimming to constant OAL on brass then turn. See if that helps

 

[Richard Coody]

be careful trimming new brass. if you index off the shoulder after fireforming you will probably have short necks.

 

[dcali]

When I turn my .308 brass, I take it stragiht out of the box, and run it onto a carbide turning mandrel until it just hits the shoulder. I do not expand it first. No, it is not always perfect, but it's close enough. But I'm not shooting benchrest. Sure works for F Class, though.

 

[Willie]

I ran into exact same thing with 40* shoulders & 21st Century cutter. I went back to K&M cutter to get in shoulder. Then, after 2 firings, made my final cut. I mistakenly thought that now the 21st Century will match my fully formed 40* shoulder. It did not, my Ackley chamber and the 21st angles just didn't jive. So, I'm just using 20* K&M cutters on everything.

 

[08glide]

I am using the Century 21 lathe and am also having this issue with new Palma brass. I can run the same brass over my K&M and have no issue cutting into the neck shoulder junction and making a nice consistent cut all around the neck. I called John and got a few pointers to try but no luck so far.

 

[Ledd Slinger]

I use the 21st century turner with 30, 35, and 40 deg cutters. But I use the drill mounted shell holders so my hands can compensate for any misalignments. Always perfectly concentric cuts on the shoulders. I thought the 21st lathe was supposed to give the same effect as free floating in my hands. Perhaps I was wrong.

I was planning on buying the lathe for my turned and holders. Might scratch that idea now.

 

[JRS]

Cartridge brass is no different than any other component. It is made to +/- specs.

 

[alinwa]

I use the 21st century turner with 30, 35, and 40 deg cutters. But I use the drill mounted shell holders so my hands can compensate for any misalignments. Always perfectly concentric cuts on the shoulders. I thought the 21st lathe was supposed to give the same effect as free floating in my hands. Perhaps I was wrong.

I was planning on buying the lathe for my turned and holders. Might scratch that idea now.

Please understand my position...... THE 21st CENTURY TOOLING IS WONDERFUL, AND I RECOMMEND IT WHOLEHEARTEDLY...... I'm just stating that new brass is very crooked, SO crooked that I. myself, NEVER do any turning without at least ironing out the necks and most often I actually blow stuff out to fit and square it all up.

Also, what your hands do is compensate "in and out" as well as for axial misalignment...... this can produce better looking shoulders because the cutter rides the existing shoulder even if it's somewhat wobbly.