I recently ran into a problem with some .260 Remington brass. My Nosler brass came with donuts and they won't take it back so I decided to make do. I noticed that my K&M neck turner mandrels don't have the the cutters on the end so what to do.
I chucked my case holder in the 3-jaw and set my rpm to about 160. I then inserted a chucking reamer and angled it towards the back of the neck. I then used thumb pressure to force the chucking reamer against the inside of the neck at the junction of the shoulder. Takes about 5 seconds per case and removes the donut just perfectly! I just hold the chucking reamer in my hand- I don't put it in the tool post or tail stock. That way I can angle it. I thought about putting it in the tool post, but there is way too much runnout in the case holder to do anything other than letting it float. My groups shrank nicely today!
Just thought I would post this in case anyone else doesn't have a good method to get rid of them.
I chucked my case holder in the 3-jaw and set my rpm to about 160. I then inserted a chucking reamer and angled it towards the back of the neck. I then used thumb pressure to force the chucking reamer against the inside of the neck at the junction of the shoulder. Takes about 5 seconds per case and removes the donut just perfectly! I just hold the chucking reamer in my hand- I don't put it in the tool post or tail stock. That way I can angle it. I thought about putting it in the tool post, but there is way too much runnout in the case holder to do anything other than letting it float. My groups shrank nicely today!
Just thought I would post this in case anyone else doesn't have a good method to get rid of them.
