Boyd Allen
Active member
How do you feel about turning necks at 300 RPM?
300 RPM for neck turning?
- Thread starter Boyd Allen
- Start date
Tim Oltersdorf
Active member
Boyd, I use my lathe to turn brass. There is usually some small wobble in the cases when I turn them, not a lot but some. I have tried many speeds and for me 500 RPM is optimal. It gives a good compromise between finish, excessive wobble and precision. Tim
Boyd Allen
Active member
Tim,
Thanks for the reply. Does your method involve the mandrel turning with the case, or is the mandrel turning inside the case neck?
Boyd
Thanks for the reply. Does your method involve the mandrel turning with the case, or is the mandrel turning inside the case neck?
Boyd
A
abintx
Guest
Boyd,
Ken Markle of the old K&M Services once told me that 180 RPMs was optimum/sufficient because it didn't generate excess heat.
That's what I use, and found that exact RPM with the purchase of the Ryobi HP41L portable screwdriver/cordless drill. I have four that I keep charged up for various uses.
When it comes to turning necks, it's a light weight tool that does an excellent job in conjunction with the K&M Microadjustable Neck Turning Tool and the K&M Case Holder/Power Adapter.
Ken Markle of the old K&M Services once told me that 180 RPMs was optimum/sufficient because it didn't generate excess heat.
That's what I use, and found that exact RPM with the purchase of the Ryobi HP41L portable screwdriver/cordless drill. I have four that I keep charged up for various uses.
When it comes to turning necks, it's a light weight tool that does an excellent job in conjunction with the K&M Microadjustable Neck Turning Tool and the K&M Case Holder/Power Adapter.
Last edited by a moderator:
Tim Oltersdorf
Active member
Boyd, I use the lathe to turn the case and a Hart neck turning tool to cut the cases necks. The neck turner mandrel is carbide which helps with expansion problems due to heat build up. The mandrel is stationary. The mandrel is a tight slip fit in the case neck and it does become warm after 7-10 cases. Even with carbide you must lube the mandrel. I lay the cutter on the lathe compound during the time it takes to remove one case and chuck up another. This acts as a heat sink to drain off some of the heat from the cutter. I do not chuck the case directly in the lathe chuck but use a case holder that is chucked in the chuck and the case is inserted into the holder. Because the PPC case is tapered it is difficult to put in a lathe chuck accurately hence the use of the case holder. Prior to getting my lathe I used a 1/2 drill held in a vice and then a drill press. Having turned many a case by hand I believe power turning at whatever speed you choose is superior. If you decide to turn cases at a faster speed I would recommend a carbide mandrel on your case neck turner. You can use a steel mandrel and I have but you must allow it to cool more frequently and after fewer cases. I turned 100 cases last night and was reminded again how much I hate doing it. Anything that speeds up the process is helpful. Tim
Way back yonder, when we had free run of a nuclear grade machine shop on graveyard shift, I set up a deal similar to Tim's except that the machine turned backwards. I turned 20 necks but it took two shifts and ruined my Marquart cutter. Talk about mandrel heating...
JerrySharrett
Senile Member
My lathe method;
Wxcuse the grungy arbor but it simply the stub of a Class 8 bolt. The left hand diameter is just slightly smaller than what you want the neck to finish.
The center diameter is EXACTLY the diameter of a bullet. That means what you turn to here is EXACTLY what you get with a bullet seated.
The right diameter is just to start the case on the arbor.
This shows a case just finished
This is a K&M case holder with a slide hammer installed. I push the case on with the tailstock using this tool
then remove the case with the slide hammer. No, I do not turn the case with this tool on the cartridge case!!
I use a tenth reading dial indicator mounted directy to the toolholder/
Hope this helps...
Wxcuse the grungy arbor but it simply the stub of a Class 8 bolt. The left hand diameter is just slightly smaller than what you want the neck to finish.
The center diameter is EXACTLY the diameter of a bullet. That means what you turn to here is EXACTLY what you get with a bullet seated.
The right diameter is just to start the case on the arbor.
This shows a case just finished
This is a K&M case holder with a slide hammer installed. I push the case on with the tailstock using this tool
then remove the case with the slide hammer. No, I do not turn the case with this tool on the cartridge case!!
I use a tenth reading dial indicator mounted directy to the toolholder/
Hope this helps...
Last edited:
M
macaver1
Guest
With the new KnM carbide cutting bit plus the carbide turning mandrel, the only heat that I notice in the KnM turning tool is mostly generated by my hand. What a arthritic hands-saving combination when used with a cordless screw driver! I can easily remove .001 from a 7RM case in one pass. With the old tool steel bit, I had to resort to mounting the turner in a block of wood routed out to hold it, and still had to make multiple passes.