Neck Turning Lubricant

CyaN1de

CyaN1de

CGN Ultra frequent flyer
Rating - 100%
89   0   0
Location
KTSA Regular
What do people use that one may have laying around the house?

I have some donuts to take out of the cases of some necks and I don't really want to go and try to find "Neck Turning Lube"

Wondering if a silicone spray lube would work well?

I have used Imperial Sizing die wax in the past but it's slow to apply and I have about 600 cases to do so preferably something that is spray on.
 
horseman2 said:
I have never used "Neck turning Lubricant" so thought this might be another joke.
Probably find it in the same isle as "Elbow Grease".
Click to expand...

Actually not a joke....Sinclair has a neck turning lube.

13730_7389_thumb.jpg


Looking for some more household product ideas that people are actually using rather than "WS-50 should work" etc...
 
I don't generally use a lubricant for each case like I would for resizing... if anything, take a bit of motor oil on your fingertip and lube the mandrel; wipe clean with a dry paper towel and just re-apply when things get tighter. Personally, I'd invest in an expander mandrel to properly size the neck ID before I'd buy a neck turning lube.

Just my $0.02, YMMV.

-M
 
Doc M said:
I don't generally use a lubricant for each case like I would for resizing[...]Personally, I'd invest in an expander mandrel to properly size the neck ID before I'd buy a neck turning lube.
Click to expand...
You need to lube to keep the heat down, as the heat will expand and distort the mandrel (altering your neck thickness).

I use motor oil.
 
Okay. So I supplose any sizing lube would work too. I think at some time I used a RCBS lube on the shaft of my FORSTER, and it rusted . . . While it is a good lubricant for it's intended purpose it is not oil based.
 
acrashb said:
You need to lube to keep the heat down, as the heat will expand and distort the mandrel (altering your neck thickness).

I use motor oil.
Click to expand...

How hot do you plan on getting your mandrel and cuter head? A 10 degree Celsius change in temp will not affect your results in any way on something that small. A 4 inch bearing race might only grow 1-1.5 thou when heated from 72F-210F. Brass is so easy to machine and creates very little heat. I would not worry about.
 
cdnredneck_t3 said:
How hot do you plan on getting your mandrel and cuter head? A 10 degree Celsius change in temp will not affect your results in any way on something that small. A 4 inch bearing race might only grow 1-1.5 thou when heated from 72F-210F. Brass is so easy to machine and creates very little heat. I would not worry about.
Click to expand...
People who turn necks are usually interested in precision, and that means ten-thou repeatability. It's easy enough to lube and reduce the heat variability, so my question is "why not"? Mandrels become warm to the touch quickly even with lube; without, or when the lube is too light, they get quite warm and the brass starts to gall (on both Sinclair and K&M mandrels).

I haven't recently measured mandrel growth, but have done so in the past with noticeable results. I have measured neck-thickness post-cutting and found unacceptable variation when I let the mandrel get "quite warm" (unscientific, but I'm not putting a thermocouple on it). Perhaps there's something on 6mmbr or a comparable forum.

Neck-turning without minimizing variance is a waste of time, as neck-turning is a minimal gain in a factory chamber with good brass in any event.

Lousy brass is a different matter. Here, an 80% cleaning-up will do wonders.... but buying better brass is the way to go when possible.
 
Last edited:
Once the mandrel heats up after about 7-10 cases (and without lubing) brass starts to build up on the mandrel under the cutter which makes the turning hard and F's up the inside of my necks.
 
acrashb said:
I haven't recently measured mandrel growth, but have done so in the past with noticeable results. I have measured neck-thickness post-cutting and found unacceptable variation when I let the mandrel get "quite warm" (unscientific, but I'm not putting a thermocouple on it). Perhaps there's something on 6mmbr or a comparable forum.
Click to expand...

I just did a little experiment here in the shop. I took a chunk of 3/8 bar stock measuring .375” at 14C. I took the torch and heated it to 200C and measured it again. It grew to .377” I let it cool a bit and measured it again at 120C and it was .376”. Even at .376” if it were the mandrel in a cutter that is minimal. You cut on the radius which takes that extra 1 thou and makes only ½ thou difference on your cut because most guys talk in neck thickness not diameter. And to be honest unless everyone is using Venire micrometers you don’t have the capability to accurately measure down to .0005”. I turn my brass using a cutter chucked in the lathe and I have never noticed any considerable heat distortion.

The brass galling up on the mandrel is a problem however. And like it was said before lube is lube. Lube up the mandrel every couple shells and you should be OK.
 
I've noticed similar things as acrashb when using a K&M neck turner, and turning the case under power. What I do now (neck turning) is about 5 cases at a time and drop the neck cutter on a bed of ice (in zip lock bag) and let cool. I also use Imperial sizing wax and while the cutter is cooling I prep the next 5 cases. All this takes is pressing the case neck first into the Imp Wax tin.

I have never had to sit down and do more then 100pcs of brass at a time so I don't notice how time consuming it is... ok I lied its F'n slow.

With donuts you would be removing a lot less brass so I would think you could get away with doing a bunch of cases before worrying about the cutter heating up if your using Some kind of lube. I'm guessing motor lube would work just fine as acrashb pointed out, stopping every once and a while to "cool da tool" with some ice.

Either way let us know how you make out, I'll eventually have to try to remove some donuts my self.

Happy turning!
 
Last edited:
I just did 40+ on Sunday and with having to remove the mandrel to clean it after every 8th or so case, I was getting the donuts out for the better part of an hour. You would be surprised how much it tightens up at the last few thou of the neck where it is thickest.

I did not lube at all because I was loading on Saturday night for Sunday shooting and did not have time to run them through the tumbler again to clean off any oils and such.

With having 600 fired cases to de-donut and another 200 new cases that need to be uniformed.....40cases/hour (approx 20 hours) just isn't gonna cut it. LOL
 
cdnredneck_t3 said:
I just did a little experiment here in the shop [....] makes only ½ thou difference on your cut because most guys talk in neck thickness not diameter. And to be honest unless everyone is using Venire micrometers you don’t have the capability to accurately measure down to .0005”.
Click to expand...
Thanks for doing the experiment - tends to validate my observations.

I measure necks with a .0001" dial indicator over another mandrel - when done right, they mostly come out exactly on the measurement I want, with a few slightly thinner, so the .0005" variance you've mentioned is significant (to me). Depending on one's need, it doesn't matter.

For those who want to measure necks accurately:
MIC-3-l.jpg

http://www.sinclairintl.com/product/8970/Micrometers
 
acrashb said:
Thanks for doing the experiment - tends to validate my observations.

I measure necks with a .0001" dial indicator over another mandrel - when done right, they mostly come out exactly on the measurement I want, with a few slightly thinner, so the .0005" variance you've mentioned is significant (to me). Depending on one's need, it doesn't matter.

For those who want to measure necks accurately:
MIC-3-l.jpg

http://www.sinclairintl.com/product/8970/Micrometers
Click to expand...

Do you honestly believe you are turning your necks to a .0001” tolerance? Yes your Sinclair gauge has the venire scale on the spindle of the micrometer but all it has done is give you the decimal point syndrome. It is easy to put a tolerance of .0001” on paper. Why not put .00001” or even .000001”for that matter.

You have a tighter tolerance than Berger has tolerance on their bullets. And I bet they spend way more money on tooling than you do.


J4 Precision Jackets are the only bullet jackets in the world known for less than .0003 total wall thickness variation on every size and lot. This has been true for decades and is provable by checking any lot. There are those who claim that they can meet this tolerance and we know that they can every once in a while, but to do this with every single lot is something that only J4 has perfected. Anyone who wants to can order jackets and check them yourself. This is an absolutely critical aspect of precision bullet performance and we are the only bullet company with this capability.
Click to expand...
 
cdnredneck_t3 said:
Do you honestly believe you are turning your necks to a .0001” tolerance?
Click to expand...
You seem excited - but then neck turning is an important topic ;)

What I said was "they mostly come out exactly on the measurement I want", which means just what it says: most measure spot-on the thickness I want, some don't. For my .308 that's 0.0145", for my .223 that's 0.0122". I understand about measurement error, and I don't use a NIST-traceable dial gauge / mandrel combination, but so what? One standard deviation is going to be slightly under .0001" in any event, but I haven't measured, recorded and calculated - no need.

The overall point, still quite valid, is that .0005" of variance from the tool alone, let alone technique, is a) easy to measure with the right tools and b) contrary to my goals. Your goals may differ.
 
acrashb said:
You need to lube to keep the heat down, as the heat will expand and distort the mandrel (altering your neck thickness).

I use motor oil.
Click to expand...

I suppose I should clarify and say that I neck-turn by hand at the moment... but I agree that using a high-speed setup would definitely mean some sort of lube.

-M
 
acrashb said:
You seem excited - but then neck turning is an important topic ;)

What I said was "they mostly come out exactly on the measurement I want", which means just what it says: most measure spot-on the thickness I want, some don't. For my .308 that's 0.0145", for my .223 that's 0.0122". I understand about measurement error, and I don't use a NIST-traceable dial gauge / mandrel combination, but so what? One standard deviation is going to be slightly under .0001" in any event, but I haven't measured, recorded and calculated - no need.

The overall point, still quite valid, is that .0005" of variance from the tool alone, let alone technique, is a) easy to measure with the right tools and b) contrary to my goals. Your goals may differ.
Click to expand...

With the proper tools it is quite possible to measure to .0001”. Hitting that size most times is not nearly as easy. There will be more than .0001” change from shooting and sizeing. Even if you are hitting that elusive one tenth of a thou tolerance it is spoiled after the first shot. All I am saying is I find hitting a tenth very hard to believe.
 
You must log in or register to reply here.
Back
Top Bottom