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Mandrel is galling up..what am I doing wrong?

Just to clarify, I am not turning the necks. I did polish the mandrel with Flitz to a mirror like finish. My goal was to uniform the necks using a mandrel and not a full length sizing die with a button so I could try and reduce my run out. The galling is occurring right at the point where the taper ends and the .242 diameter begins.

In a couple of hours I will be able to try some of the ideas you all have mentioned and get back with you.
 
I polish my mandrel with flitz after running with 1000 wet dry. Once brass builds up on mandrel it gets worse quick. It will then gauld your necks. Need to keep clean. I use Imperial die wax. Matt

+2 on Imperial wax
 
To the OP and Guys/Gals

Many thanks for this thread.

Every time I come on here, I learn something!!!

I am going to use a diluted mixture of STP and graphite when I next do some neck turning. I have used a stiff mixture of STP and graphite on my air rifle piston and it works superb. Why didn't I think of doing this as lube for neck turning???? :eek::D

Cam
 
I don't use lube on my turning mandrel either (granted it has a titanium nitride coating). So long as my case necks are properly annealed where they stay exactly where the expander mandrel sets them, there's no need for lube. I've found that the only time I can't get cases to fit on the turning mandrel without galling is when they are beginning to develop a donut at the base of the neck. Of course I always try to avoid this by turning down onto the shoulder. But i still get donits from time to time on certain cases. Once the donut is there, the case is doomed.
 
I've had the same problem with new brass. Lapua and Peterson. Normally I use dry lube but with new brass I have to use something better. Ballistol works for me.
 


SINCLAIR STAINLESS STEEL EXPANDER MANDRELS

https://www.sinclairintl.com/reload...inless-steel-expander-mandrels-prod33134.aspx

Our neck turning tool mandrels are made from high grade stainless steel on Precision turning centers. The shape, finish, and size are the result of years of use and experimentation by many hand loaders. All of our mandrels fit both our NT-3000 and NT-1000 neck turning tools and most of our older model neck turning tools. Our neck turning tool mandrels measure approximately about .002"" less than the bullet diameter for the caliber. Our expander mandrels are made .001"" larger than the turning mandrels. Using an expander mandrel prior to neck turning sizes the case to fit the neck turning mandrels perfectly. This correct fit makes the turning process more precise and much easier. Any of the mandrels can be used to ""neck"" cases up to the next caliber when used with the NT-EXP (Expander Body).



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It wold be nice if Sinclair gave the Rockwell hardness of the SS. Many common grades of SS can only be hardened by cold working, some are heat treatable. If the mandrels were machined on a lathe it's difficult to cut metal with a metal cutting tool if the hardness is above about 35 Rockwell "C" scale. Ceramic inserts can cut harder steel. If you can scratch the non working end of the mandrel to any depth with the corner of a razor blade it isn't real hard. In any case a good lube should work. I worked in Petroleum research for 20 years. I like oil lubes. The higher the viscosity the thicker the protective oil film. Thick oils are harder to remove.
 
My solution to the new Lapua brass gauling is to put it in a vibratory tumbler using walnut media for about 4-6 hours before I do anything to them. That beautiful annealing on the factory cases seems to have quite a bit of oxidation and that oxidation is coming off on the mandrel and in dies . I have screwed up several dies and expanders before and this seems to work every time.

The expander mandrels, I do like dkhunt, and polish them. Except I use a little 1500 grit wet or dry, lubed with a drop of penetrating oil.

This is the answer to the OP’s problem. Polish the inside of those fresly annealed cases.
 
I used to use that die. Here's a previous post of mine on mandrel dies.


Some of us know that, of the 3 components of the Holy Trinity of precision ammo (powder, seating depth and neck tension), neck tension is the most difficult to control.

I know that everyone likes to control neck tension with bushings but to me that doesn't seem like a very good way. From my way of thinking bushings transfer any variance in neck thickness to the inside of the neck where they have a direct impact on neck tension. That is not a good thing, because no matter how careful you are turning necks there will be variances, and those variances will impact neck tension.

I believe that the outside of the neck has minimal importance, as long as there is a minimum .003 neck clearance for bullet release. The only important thing is how thick the necks are because that has an influence on spring-back. IMO the part of the neck everyone should be focusing on is the inside of the neck, or more appropriately inside diameter. The inside diameter is what influences neck tension, if one can transfer neck wall variances to the outside of the case it is that much better.

So the question is: How do we control neck tension from the inside of the neck? What if instead of honing die necks (an irreversible and often problematic process because dies are hardened, not to mention that you have to be twice as accurate with a die then with a mandrel, an impossible taskfor most small machine shops) we were to use a mandrel to expand the necks to provide the desired neck tension? What would a mandrel do?

Well, ... a mandrel would control the inside diameter of a case neck much more precisely than any bushing ever can. It could also transfer neck thickness variances to the outside of the neck where it doesn't interfere with neck tension and bullet release. That's good isn't it?

I have been using mandrels for thousands of cases. The problem is that just when I have a mandrel that gives ideal neck tension (down to .0001 precision) it starts to wear, and after a couple of thousand cases it is done. Making another mandrel to .0001 precision is very difficult/not possible for most machine shops and grinding shops. So I set out to look for a solution. I eventually focused on the Hornady bullet puller collet, because that's what I had. I started using the bullet puller to hold pin gages to expand the necks to match the turner mandrel.

However, the bullet puller did not hold the pin gages as co-axially straight as I wanted, so I approached Kenny Porter ( kennethp@portersprecisionproducts.com ), who makes all kinds of things including parts for pacemakers (can you think of anything more critical?). I told him I wanted him to make a die for me that would hold a pin gage, actually a range of pin gages ie .305, .306, .307, .308 and .309. Once I showed him what I had in mind he made a leap to a collet that is ideally suited for what I wanted. The collet holds the cutting bit for a CNC machine. It has real holding power. Here’ the mandrel die that Kenny Porter made for me.


neck-expanding-die-1-jpg.1019762



neck-expanding-die-3-jpg.1019763




Pin gages are small tubes 2" long and can be bought for a few dollars and they are available in dimensions as exact as .0001 (+/- .00002). They generally have a 60 to 62 Rockwell hardness, like tool steel. They are ideal for this purpose, all you have to do is bevel the tip. To bevel the tip all I do is chuck the mandrel in a drill and spin it against a grinding stone until I get the tip that I desire. Takes less than 5 minutes.


Now, when I need a new mandrel I buy a Vermont Gage pin gauge. If you’re looking for +/- .0002 precision they are round $3 each. If you really want to get precise and have a mandrel to .0001 (+/- .00002) precision then the price jumps to around $18 and you’ll have to order directly from Vermont Gage. For $18 you get a mandrel and a certificate of accuracy and the name of the guy that inspected and when.

This mandrel die makes all other mandrel dies I have seen or bought look primitive.

Joe

That's slick ;) Looks like he just incorporated a milling machine ER tool holding collet into a die. That would work well. Self centering, can clamp various size pins and gives maximum holding power.
 
A cheaper alternative to carbide mandrels or the ER collet system from Ken Porter, just send all your mandrels to a salt bath nitriding operation. The melonited parts or barrels are hard enough that none of my files will bite into them.

My 21st Century turning and expanding mandrels never galls. On my 650s, on position 1 is the universal expanding die with the appropriate caliber, no lube, no problem, lost count how many Ks have been loaded through these presses. That's for my own consumption and for a couple of friends who come over and load their short line ammo.
 
I turn custom sized spuds for M dies out of O1 drill rod.These are for tack driving cast bullet rigs...... each rig/load may see It's own spud size variation.

Anyway,they don't get "polished" and don't get any further hardening.Leaving a tiny bit of roughness,basically what a Lyman spud finish is,actually reduces friction.Good luck with your project.
 
Ive been using STP on a carbide mandrel and there isnt any issue, neck size just needs to be under the size of the mandrel. The few Ive turned on ferrous mandrels respond well to polishing and STP. Lubing both e mandrel and the neck pretty much eliminates galling or heating. Stopping and relubing if turning force starts to increase avoids heating. Carbide is still the most positive solution.
 
Inside the neck I use 3-IN-One Dry Lube (you apply it wet and then it drys instantly) applied with a foam head Q-tip that is made for cleaning electronics. It also works great for seating bullets.
 
I was trying to use a Sinclair gen 2 die with a 6mm expander mandrel on new Lapua 6Br blue box and the mandrel kept galling up and scoring the inside of my necks. My initial lube was imperial dry neck lube, after removing the copper off the mandrel I tried some lyman case lube I had. Still no luck. I even polished the mandrel to a mirror shine and went back to the dry lube and it galled up.

What am I doing wrong? I measured the mandrel and it does measure .242in like its supposed to.
Try Hornaday one shot spray lube follow directions spray down word at a 45° angle so I’m goes inside the neck it works great for me
 

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