Forster Neck Turning Question

[djarecke]

Gang,
I got a Forster outside neck turner for my Forster case trimmer, and all of the cases are turning out like those in the photo. It seems to be doing a great job in terms of consistency, but as you can see in the photo, the trimmer goes down closer to the shoulder on one side of the case than it does on the other. Is this an issue that might affect accuracy and just the way they turn out with the Forster? I have a hand-held trimmer and don't remember it being this way.

 

[Clark]

Have you measure thickness runout around the neck with a ball micrometer?

I think I have a Forster neck turner, but I have been turning necks on the lathe. I am never satisfied with the run out I get.

 

[Fuzzball]

Your photo is common and shows you're actually accomplishing something useful. The external cut is controlled by the pilot inside. If the cut was concentric it would indicate that all you're doing is thinning the necks which, of itself, is rarely helpful.

 

[djarecke]

I did measure the new run out, and the worst one was .001". If there is any runout, 9 times out of 10 it's imperceptible on my case inspector.

 

[Clark]

The Lee collet neck die is not so susceptible to thickness run out, but with other sizes it should proportionally go into seated bullet run out.

 

[ZiaHunter]

You should set the cutter so it cuts slightly into the shoulder to prevent doughnuts and would recommend getting a ball micrometer so you can accurately measure neck wall thickness. If you are going to turn for different calibers, you may want to think about buying additional cutter heads so you don't have to adjust the cutter between setups. Bought my Forster setup in 1973 and still use it on occasion.