Turned a lotta necks

Hi Jackie , i also will be trying the .269 shortly and will turn town to a .267 finished nk. can you let me know which bushing is working for you.

Remy
 
I turn the necks to where when loaded with a typical Benchrest Bullet with a diameter of .2434 at the base, the loaded round will measure .2675 at that point in the neck.

A .265 bushing seems to work fine with this.
 
jackie schmidt said:
I turn the necks to where when loaded with a typical Benchrest Bullet with a diameter of .2434 at the base, the loaded round will measure .2675 at that point in the neck.

A .265 bushing seems to work fine with this.
Click to expand...

Seriously guys, have neck diameters .262, .263, .265, .266, .268, .269, etc EVER shown ANY dominate traits toward better accuracy?


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Finally a breath

JerrySharrett said:
Seriously guys, have neck diameters .262, .263, .265, .266, .268, .269, etc EVER shown ANY dominate traits toward better accuracy?


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of reason.The predominate neck on "winners" cases have been .262 or .263 if they are being honest. If you are going to turn, why stop at .268 or .269?
 
Ease of turning, one pass. I can't tell the difference on paper in any size one way or the other.

We hashed this all out years ago. If you are currently invested in the .262, no reason to change. But if you are just starting out, there is no reason not to go to a .269, or even .270.

I tried the no neck turn 274, it shoots as good as anything. But there is always the thought that you are leaving something on the table.
 
Makes my Bosch 3.6 volt cordless drill look a trifle anemic, though it does run at just the right speed to uniform primer pockets. :eek:
 
Jackie,
Thanks for posting the video. Very nice. I tried turning this way just last week. (I don't have a turret attachment though, just used the tailstock.) The first few went fine, but then by the fifth case, something shifted so that I had 5 tenths runout on the neck thickness. What could possibly shift in a collet/collet chuck??? Several things, obviously, but still wondering where to look first. Any advice?

In the mean time, I went back to a Stiller. Getting a variation of about 2-3 tenths on neck thickness as the mandrel temperature changes. Much less than the K&M, but still room for improvement. There is no friction to heat the mandrel in lathe turning, so it should be the more consistent method.

Thanks,
Keith
 
There is a reason. Turn. Turn. Turn.

I switched to .268 necks years ago. I used to use .262 and then .263 necks. I always turned the necks in one pass then and now. I never saw a difference in shooting between the different size necks or in turning them in one or two passes. Try a carbide mandril on your turner. My neck thickness variation is usually .0001". One advantage of the thicker necks is that when you drop them on concrete they don't dent. The disadvantage was the lack of carbide bushings large enough to size them. I now use one piece dies so I don't know if anyone makes the larger diameter carbide bushings. Any one know a source of larger diameter carbide bushings? Tim
 
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mks said:
Jackie,
Thanks for posting the video. Very nice. I tried turning this way just last week. (I don't have a turret attachment though, just used the tailstock.) The first few went fine, but then by the fifth case, something shifted so that I had 5 tenths runout on the neck thickness. What could possibly shift in a collet/collet chuck??? Several things, obviously, but still wondering where to look first. Any advice?

In the mean time, I went back to a Stiller. Getting a variation of about 2-3 tenths on neck thickness as the mandrel temperature changes. Much less than the K&M, but still room for improvement. There is no friction to heat the mandrel in lathe turning, so it should be the more consistent method.

Thanks,
Keith
Click to expand...

Keith, you may have done this but if not, snug the gibs down on the cross and compound feeds once you have them set to cut the desired neck thickness.
I've turned neck this way with good success..measuring within a tenth. I use a tapered mandrel to neck the cases up and then turn at the same setup.
 
I switched from a .262 neck to a .268 several years ago. The only advantage that I've seen is the 268 can generate more grip/tension on a boattail bullet. I got tired of going to the line with a stiff load of V133 and having 5 different seating depths before I could shoot. The 268 neck wrapped all that up!

Bart
 
The article I wrote years ago on neck turning in an engine lathe is probably still in the archives somewhere, Mike Bryant also has an excellent article.

One thing you have to be absolutly sure of is you turned mandrel does not shift in the chuck or collet. That, in my opinion, is the only reason you could get a wall thickness variation in a case.

Once I get my mandrel turned, (to the exact size of the biggest part of the bullet), I simply push the cases on and, after I get the correct diameter, lock every thing down, and go to town.

One thing I did not show because it got in the way of the picture is I do use a mist cooler to keep the mandrel temperature constant.

Also, and I will be the first to admitt this, it helps to have a Monarch EE tool room lathe when working in production runs and doing them this quickly.
 
Mike and Jackie,
Thanks for the replies. I did tighten the crossfeed, but the neck thickness developed runout. I have yet to put an indicator on it, but pretty sure the mandrel must have shifted. This is the first job for this collet chuck (a 2J handwheel type), so maybe the backing plate is not secure on the lathe, or the collet or the rod has a burr, or ??? When I get some time, I want to solve this problem, because I see a fundamental issue with hand turning - that it is hard to control the amount of heat generated by the neck sliding on the mandrel. Thicker necks and necks with smaller ID create more friction, increasing mandrel temperature and causing a heavier cut.

Jackie, the lathe I am using is a 10EE. I know it should do an excellent job if I can get it set up properly. The jobs it can do are a bit limited, but it is such a pleasure to operate. It looked like you were hand feeding quickly in to the shoulder and then doing a slow automatic feed back out the mouth. That's what I was trying as well.

Thanks,
Keith
 
That's how I do it. Remove the stock by hand, kiss the shoulder neck junction, and the power feed back to the chuck is the finish.

I can't emphasize enough on how important it is to have the mandrel running dead true. What ever it runs out, that will be the variation in your case wall thickness.

People have asked if I reuse the mandrel. No. You simply cannot indicate it true enough. Turning a new one each time is the only way to insure it runs as true as the machine will turn.
 
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I've used a similar lathe process Jackie. And as stated, that mandrel has to run true in the chuck. Otherwise it's all for naught.

One more bit of advice.....feed in slow. If you go too fast the neck will get hot and expand off the spud.

.224 Clark neck turning pictured (carbide mandrel and cutter)

224_Clark_16.jpg


224_Clark_17.jpg


-Lee
www.singleactions.com
 
mks said:
Jackie,
Thanks for posting the video. Very nice. I tried turning this way just last week. (I don't have a turret attachment though, just used the tailstock.) The first few went fine, but then by the fifth case, something shifted so that I had 5 tenths runout on the neck thickness. What could possibly shift in a collet/collet chuck??? Several things, obviously, but still wondering where to look first. Any advice?

In the mean time, I went back to a Stiller. Getting a variation of about 2-3 tenths on neck thickness as the mandrel temperature changes. Much less than the K&M, but still room for improvement. There is no friction to heat the mandrel in lathe turning, so it should be the more consistent method.

Thanks,
Keith
Click to expand...


Keith, a few things I found important to get top quality results using a lathe to turn necks'

1) the stud diameter you press the chamber neck onto needs to be finish turned after it is chucked up before using it to turn brass so it will run true..

2) AND if you will turn that stud diameter to EXACTLY the diameter of your
bullet, the diameter you measure after the cut will be exactly the diameter the brass will be wit a bullet seated.

3) Using a magnetic base I mount a 0.0001" dial indicator to the back of the tool post to accurately control diameter.

142evd1.jpg






.

EDIT- I also press the brass on and remove it with a slide hammer shown. You can easily make one out of a K&M holder, a piece of all thread and then put a center on the end of the all thread. Remove the slide hammer for each change of brass.

6s540h.jpg





EDIT 2- What probably caused your runout is in pressing the brass on the arbor you evidently scooted the arbor in the collet. Use a universal chuck and chuck the stud very tightly, then like I said above, take the finish cut on the stud.


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I just noticed in my video, you can't read the Mic's. Here is a picture.

http://www.youtube.com/watch?v=qmqwoZ5xjWc

As Jerry noted, I turn my mandrel to exactly the same size as the base of the bullet. That way, what ever I measure is what a neck with a seated bullet will measure.

As you can see, I run about .00016 clearance in my .269 neck.
 

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