Neck turning speed???

[tred1956]

I am new to neck turning and was wondering , what would be the ideal RPM to turn the case to avoid over heating? Let me also ask what would be the max speed before you overheat and damage brass?
Thanks
Doug

 

[searcher]

The proper speed, based upon the mandrel fit to your brass, type of lube used, etc. will dictate the best speed. I use a Sinclair neck turner and find it best to go as SLOW as possible. If I had to guess how many R.P.M.s that is, I'd say maybe 25. I use a DeWalt 18v drill that has three speeds and use the lowest speed setting, even then not fully depressing the trigger to give me more control. I know there are true lathes being used specifically designed for turning brass but I have not used them. This "slowest speed" works for me. You will likely find that you won't get into much trouble going real slow. It is when you try to speed things up that you will inevitably get a neck too hot and the brass will expand, creating uneven cutting or just get too soft and will try to "roll-over" on itself and tear.

 

[bdale]

I to have a Sinclair neck turning tool the 1500 model and i just use a black and decker cordless screwdriver and imperial wax after i get them turned i take and spin them between my fingers and some 0000 stealwool to smooth and polish them up.

 

[BigDMT]

1st gear on a DeWalt cordless XRP 18V drill

21st Century neck turner and drill adapter. Works great and produces perfectly smooth and uniform wall thickness.

 

[Bradsb]

It has been my experience that expanding mandril to turning mandrel fit is way more important than at what speed the brass is turned. When I first started turning the fit was so tight on the turning mandrel that no mater how slow I went everything would get to hot after only a couple of brass. After I matched up the two mandrils better turning worked great anywhere from 25 to 300 RPM with somewhere in the middle being the easiest to controll.

 

[Bowhunter4]

I also use a 21st century Lathe. After a couple of cases you will find the right speed. I use a cheap black and decker drill and don't even use the max speed.

 

[LHSmith]

Per Ken Markle, founder of K & M Precision Shooting products and designer of the K & M neck turning tool, the answer is 180 rpm.

 

[tred1956]

Thanks for all the replies.

Safe shooting
Doug

 

[jlow]

Heat is affected by turning speed but also by how deep a bite you take out of your neck. Always use the expander mandrel that is made to be used with the turning mandrel you are using.

 

[BigDMT]

I do usually go pretty slow during the first pass down the neck. Once the first pass is complete, I give my DeWalt drill full throttle on 1st gear and pass 2-3 more times. Makes perfect necks and operation is very smooth

 

[rogn]

Ive got a carbide mandrel in 6mm and use RCBS sizing lube(STP would work too) and any low speed cordless I pick up. I run as slow as it cuts well on the first pass. Just want to cut even and cleanly. Finish pass is 2 or more passes at some higher speed. Complete clean up of the lube w/ hot water and degreasing soap.

 

[GPat]

Currently I use a Benchrite Case Lathe, a PMA Neck Turning Tool (of course) with carbide mandrels and PMA Neck Turning Lubricant. The Benchrite spins the cases at 180rpm and that combination gives a great finish.

My alternative setup is either a Sinclair Case Prep Motor (200rpm) or a Dewalt Power Screwdriver that is variable speed, running somewhere in the middle of its range. I've used the Dewalt at its highest rpm and that actually works well too as long as the cutter and mandrel are both carbide and you're using adequate lubrication.

I've found that the most critical factor in avoiding heat is the mandrel fit and good lubrication. I recently turned 50 pieces of Lapua 30-06 cases in about 45 minutes and didn't get any heat at all. The mandrel fit was perfect.

 

[BigDMT]

... I've used the Dewalt at its highest rpm and that actually works well too as long as the cutter and mandrel are both carbide and you're using adequate lubrication.

I've found that the most critical factor in avoiding heat is the mandrel fit and good lubrication. I recently turned 50 pieces of Lapua 30-06 cases in about 45 minutes and didn't get any heat at all. The mandrel fit was perfect.

I use 21st Century Shooting titanium nitride mandrels with the same results. I believe carbide or titanium nitride is the only way to go. Stainless is okay, but there's a definite difference with the two aforementioned metals. Of course they cost twice as much as stainless, but well worth it IMO.

 

[amlevin]

. I believe carbide or titanium nitride is the only way to go. Stainless is okay, but there's a definite difference with the two aforementioned metals. Of course they cost twice as much as stainless, but well worth it IMO.

Both have lower friction characteristics than the Stainless. I prefer carbide but will also use a well polished Stainless mandrel if I have to.

For some reason the stainless mandrels I've seen are rougher than a gravel road. Look like they've just been turned and tossed in the box. No polish at all. Carbide's are ground and far smoother. Heat's never been a problem for me when using the carbide.

 

[STS]

It has been my experience that expanding mandril to turning mandrel fit is way more important than at what speed the brass is turned. When I first started turning the fit was so tight on the turning mandrel that no mater how slow I went everything would get to hot after only a couple of brass. After I matched up the two mandrils better turning worked great anywhere from 25 to 300 RPM with somewhere in the middle being the easiest to controll.

Absolutely 100% correct. And to add to this, each particular brand, caliber and targeted neck thickness can require a slightly different size relationship between the expander and turner mandrels. I make my own turning mandrels based on how the brass reacts when turned. It's very important not to get the turning mandrel fit too tight.

 

[jlow]

I think the correct word is to fit properly.... Too tight and you get the heat problem and too loose you will get a bad cut. That is why you should always get the expander put out by the same guy who put out the guide.

 

[Juma]

I do usually go pretty slow during the first pass down the neck. Once the first pass is complete, I give my DeWalt drill full throttle on 1st gear and pass 2-3 more times. Makes perfect necks and operation is very smooth

Spot on. Use good lube. Use Hornady for our necks.Clean and no chatter.

 

[Firearmsunlimited]

Per Ken Markle, founder of K & M Precision Shooting products and designer of the K & M neck turning tool, the answer is 180 rpm.

Agree 100%. I use the Harbor Freight Bauer cordless screwdriver that runs at 180 rpm max. I can't hold my Bosch variable speed at a constant 180rpm.

 

[mikecr]

Much of it also comes down to how much you're taking off with each turn.
I have self imposed a 1thou limit with each turning.
I think my Neil Jones turning lathe is around 180rpms

I also totally agree about the critical importance of good turning mandrel fit.
This is one of the reasons that I ONLY turn NEW cases. With this, perfect mandrel fit is usually easy.
If you fire the necks, and FL size them down, and expand back out, then that's a couple steps less likely to benefit this endeavor. Plus, you miss an opportunity to mitigate donut formation.

 

[dfrosch]

I'd bet Doug has figured it out in the last nine years.