30 BR brass turning troubles...

[the long shot]

I am new to wildcats and of course new to 30 br. I necked up my 6 br brass to 30 with two passes using a K&M 6 to 30 mandrel. Now I am trying to turn my cases down on the neck with a Sinclair neck turning tool. My problem is the cutter cuts into the shoulder because the cutter angle. I have read you just want to cut just into the shoulder but not take any off the shoulder itself. The cutter cuts fulling onto the shoulder in order to cut into it. (clear as mud right?). If I reverse the cutter the other side has a sharper edge that does not cut fully onto the shoulder but I have to turn the case counter clockwise. What am I doing wrong? I am new to turning cases and would appreciate any advice... :'(

 

[MrMajestic]

The cutter cuts fulling onto the shoulder in order to cut into it.

?????
What brand tool are you using?

 

[the long shot]

Sinclair
http://www.sinclairintl.com/.aspx/pid=35271/Product/Sinclair-Premium-Neck-Turning-Kit

 

[AlNyhus]

You definitely do not want to reverse the cutting direction. As you back the case off the cutter, keep turning it in a clockwise direction. You'll see some fine brass 'fuzz' as you do this. That's normal as it's cleaning the tops off of the small ridges that are left from the initial 'going forward' cut.

If...when you get down into the shoulder...the cutter cuts deeper on one side of the shoulder than the other, that indicates the neck is skewed relative to the long axis of the case. In other words, the neck is slightly bent from the expanding prceedure. Expanding the necks in one quick pass with a nicely tapered mandrel reduces, but doesn't completely eliminate, this tendancy.

When I cut the necks on 30BR brass, I run the expanded cases through a f.l. die with a .335-ish bushing to straighten the neck out. Put a small spacer under the neck bushing to raise the bushing up enough so you don't size the 'lump' at the bottom of the neck that forms after expanding the necks. This lump is what used to be the shoulder of the 6mm neck, but it's moved outward when expanding to .30..thus becoming the lower part of the new neck.

After you do this, set the cutter to cut the 'lump' off w/o touching the neck. Now you can cut the necks and have a nice blend into the shoulder. If you need to expand the neck a bit to fit your tunring mandrel, the necks will still stay straight as you're only expanding a thou. or two.

For what it's worth....-Al

 

[bozo699]

The L.S,
What cutter do you have, they have different angles for different shoulders, I know when I have left the cutter for my 6*284 in the turner and try turning 6br or visa versa the shoulder gets hit, make sure you have the right tool for the job, best of luck and let us know what you find
Wayne.

 

[the long shot]

AlNyhus

I believe you identified the problem...

"If...when you get down into the shoulder...the cutter cuts deeper on one side of the shoulder than the other, that indicates the neck is skewed relative to the long axis of the case. In other words, the neck is slightly bent from the expanding prceedure. Expanding the necks in one quick pass with a nicely tapered mandrel reduces, but doesn't completely eliminate, this tendancy."

The problem is I have to do another step to get this brass ready. Would I do alright just passing it over the mandrel again instead?

 

[artbosco]

I am new to wildcats and of course new to 30 br. I necked up my 6 br brass to 30 with two passes using a K&M 6 to 30 mandrel. Now I am trying to turn my cases down on the neck with a Sinclair neck turning tool. My problem is the cutter cuts into the shoulder because the cutter angle. I have read you just want to cut just into the shoulder but not take any off the shoulder itself. The cutter cuts fulling onto the shoulder in order to cut into it. (clear as mud right?). If I reverse the cutter the other side has a sharper edge that does not cut fully onto the shoulder but I have to turn the case counter clockwise. What am I doing wrong? I am new to turning cases and would appreciate any advice... :'(

In addition to Al's very cogent remarks, here's this site's technical tip you might also find very helpful [great pictures too]: http://bulletin.accurateshooter.com/?s=Optimize+Cutter+Angle+for+Improved+Neck-Turning&submit=Search

 

[mikecr]

You could just turn it while at 24cal, then expand to 30cal.
Use 2or3 culled cases for trial & error, until accounting for the thinning in expansion.

 

[the long shot]

I think I am going to try the 40degree cutter first instead of a spacer and resizer die though that would work too.

Thanks Outdoorsman

 

[artbosco]

I think I am going to try the 40 degree cutter first instead of a spacer and resizer die though that would work too.

Based on this diagram: http://www.lasc.us/Brennan30BR_Bench_Rest.htm , [thanks to Dave Berg], you might want to try 30 degrees first. Just a suggestion.

 

[AlNyhus]

The 30 degree cutter is what you want. ...if your aim is to make a perfect 'blend' into the shoulder. But if the neck isn't straight relative to the case body, you'll never get a perfectly symetrical blend. That's the whole point of straightening out the neck prior to neck turning. The spacer needed to raise the bushing up can be as simple as a 10 cent 'o' ring from a hardware store.

Another way to insure a nice 'blend' is to face off a shell holder by .020-.025, then push the shoulder back in your f.l. die using this shell holder. Now you can cut down to where the 'pushed back' shoulder is and stop w/o doing any blending. When the case is fired the first time, the shoulder blows forward and you have a perfect 'blend' with no sharp edges or stress risers to cause neck seperations later. This is how I've been doing mine for some seasons now with good results.

Good shootin'. -Al

 

[308ocd]

You might want to look at the neck turning lathe from 21st Century. It will turn your necks in one pass and John (proprietor of 21st Century) will grind an angle on your cutting tool to perfectly match the neck angle of the brass your are turning. There is no guess work that may lead to purchasing cutters for which you ultimately have no use. An added benefit of this lathe that you won’t find elsewhere is the free floating shell holder and turning tool. It gives the most concentric turn of anything on the market. Near perfect. Salazar did an excellent review on this site that is worth a look. Here is the link.

http://www.accurateshooter.com/gear-reviews/neck-turning-lathe-from-21st-century/

 

[mikecr]

Gettin pretty commercial here...
This isn't a turner issue, so none of that hokey pokey changes anything.

 

[bozo699]

Gettin pretty commercial here...
This isn't a turner issue, so none of that hokey pokey changes anything.
[/quoteMike,
What are you saying? please explain.
Wayne.

 

[mikecr]

I'm saying that OP doesn't have a turner problem.
He doesn't actually have a problem at all.

 

[artbosco]

You might want to look at the neck turning lathe from 21st Century. An added benefit of this lathe that you won’t find elsewhere is the free floating shell holder and turning tool. It gives the most concentric turn of anything on the market. Near perfect.

Actually, John incorporated the free floating aspect from the normal hand movement that your body provides naturally when using a tool such as a K&M Turner or a Sinclair Turner or any of the others out there.

When the lack of a compensating move in his original design was identified, and the rational provided for a redesign, John did what he does best: he listens, designs or redesigns, and then manufactures the next prototype for further scrutiny or acceptance. In addition to being a gifted machinist, he's the only small business owner that I know of who really listens and then brings his value added improvements to the market place ... in blinding speed.

The fact that the free floating aspect is incorporated into his tool doesn't mean that your hand stops doing what it always did. Your hand will continue to make the compensating move that the joint on the lathe now performs. The lathe doesn't make all the other turning tools out there obsolete. It only means that they lack the new bell or whistle [the joint].

 

[bozo699]

You might want to look at the neck turning lathe from 21st Century. An added benefit of this lathe that you won’t find elsewhere is the free floating shell holder and turning tool. It gives the most concentric turn of anything on the market. Near perfect.

Actually, John incorporated the free floating aspect from the normal hand movement that your body provides naturally when using a tool such as a K&M Turner or a Sinclair Turner or any of the others out there.

When the lack of a compensating move in his original design was identified, and the rational provided for a redesign, John did what he does best: he listens, designs or redesigns, and then manufactures the next prototype for further scrutiny or acceptance. In addition to being a gifted machinist, he's the only small business owner that I know of who really listens and then brings his value added improvements to the market place ... in blinding speed. The fact that the free floating aspect is incorporated into his tool doesn't mean that your hand stops doing what it always did. Your hand will continue to make the compensating move that the joint on the lathe now performs. The lathe doesn't make all the other turning tools out there obsolete. It only means that they lack the new bell or whistle [the joint].

I agree 100% with this statement, John is tops in my book
Wayne.

 

[the long shot]

The more I read AlNyhus comments about the shoulder blend the more I want to smack it with a fl die. I am a little hazy on the O ring idea though. Do I place the o ring on the shoulder and then run the cartridge up into the die? Would this push the shoulder back considerably? Why face off the shell holder?

 

[the long shot]

What can I use for a spacer?