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

[bored184]

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.

 

[expiper]

use white powderd graphite or a mix of synthetic motor oil and STP (50/50)....there are lots of formulas that work ,,these are the two I use,,,Roger

 

[AckleymanII]

couple of things to think about:

Put a heavy chamfer on the inside of the case mouth, NOT just a deburr

Id of your case neck vs Mandrel size

lube the inside of the case neck when you are expanding, you maybe scoring your necks at that point

SPEED YOU ARE TURNING NECK AT*******HEAT Maybe KILL'EN YOU!!

Lee Sizing wax in the tooth paste container works better than petroleum products I have used. Use a Q tip, dab on the inside of the case mouth, dab on the mandrel
good to go. I have used the Lee Sizing wax in a slow drill press at 120 rpm when I had a couple of thousand case necks to turn back during the p. dog wars, and in variable speed 1/2" drills(speed adjustment in the trigger). These two methods never loaded up the mandrel with brass.

I washed the cases in Coleman Lantern fuel to remove the Wax...easy. Dump them in a bucket, cover with fuel, slosh around with hand, use a paper towel in a large funnel to filter dirt and chips as you pour the fuel back in the can for future use. Put the cases on a large towel and let cases dry in the sun...does not take but a few hours.

ON another note, wax coated bullets reduce Standard Deviation down into the single digits fast and quick due to eliminating friction as the bullet enters the lands...amazing thing to witness. Reduction of fouling is amazing. Since the lee wax is so inexpensive, there is no market for waxing bullets....so no one has promoted it. If money can not be made off a product, it is no good.
Long range shooter will see amazing reductions in extreme spreads by waxing bullets, Carnuba wax has grit in it...don't use it.

 

[NA Woody]

Lee sizing lube is all I use anymore. I’ve tried a bunch of others over the years but now only use Lee for sizing and inside necks before expanding with a mandrel or turning necks. It dries quickly, never have stuck cases and it cleans up easily. If it has a downside it is slow to use for large batches.

Ackleyman- how do you apply the lube on bullets?

 

[dkhunt14]

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

 

[JohnnyJohnson]

Two things I did when I had this problem with my 30BR one I added just a tad of bar oil to my lube and I polished the mandrel until it looked like chrome with my cordless DeWalt and Flitz. Didn't have another issue after that.

 

[Uncle Ed]

Make sure your expander is .001 larger than your turning mandrel and you have approximately .0005 clearance around the mandrel and neck.

And just like a cars main bearings the case neck should float on a film of oil between it and the mandrel.

I polished my sizing dies expanders for more more bullet grip and had problems with brass bulidup on the mandrel. I now use my Sinclair expander die and make sure the neck is expanded .001 larger than the turning mandrel.

If you are turning at high speed then use car motor oil made with friction inhibitors and change it every 3000 miles.

The above is meant as humor but tight clearance and improper lubrication causes the galling. The case neck needs to float on a film of oil between it and the mandrel.

 

[Dusty Stevens]

Check the hardness on the back of it with a file. Ive seen some that wasnt hard enough and like a sizing die it will gum up very fast if its not hardened enough.

 

[KMart]

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.

 

[nmkid]

I had the same problems with Sinclair turner mandrel and the expander mandrel. I used to keep a bowl of crushed ice to keep cases and the turning mandrel cool! I then ordered an expander and turning mandrel from K & M and my troubles were over. No more bowl of ice. LOL.

 

[Gabe22BR]

I use the Sinclair turning lube, no problems with expanding or turning, on my gen 2 .

 

[One Shot One Thrill]

I only use carbide and works great

 

[dkhunt14]

I don't think he's turning, just expanding. At least I didn't read it. Matt

 

[Uncle Ed]

Instructions For Sinclair Generation II Expander Dies
https://www.sinclairintl.com/userdocs/learn/Gen_II_Expander_Die_Inst.pdf

"Be sure to lube the inside of the case neck before running a piece of
brass over the mandrel. This can be done with a cotton swab or by
dipping the case mouth into the lube. We recommend using FP-10,
any of the sizing die waxes, or any sizing lube (Redding, RCBS,
Rooster, etc.)."

I use a needle oiler with FP-10 in it like below and put one or two drop on the mandrel.

 

[ebb]

After you polish it put it in a pan of slick 50 and simmer on stove for a few hours.

 

[AckleymanII]

dk, you are correct. Jeez, hard to imagine gauling up just using an expander.

That being the case, Dusty hit the nail on the head. Polish the heck out of it, stick it in a fast 3/8" drill and go to town with 1000grit and Flitz. Then go to 1200 grit.

 

[Uncle Ed]

What am I doing wrong? I measured the mandrel and it does measure .242in like its supposed to.

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.

I went back and read your post above twice and the light bulb came on and I said BINGO.

You have a 6mm or .243 diameter bullet, the neck expander is .242 or .001 smaller than bullet diameter.

You have the .242 expander mandrel and need the .241 "turning" mandrel to give you the proper clearance.

Meaning Sinclair sells two mandrels, one for normal neck expanding and one mandrel for neck turning.

749-001-182WS
6mm (.242") Stainless Expander Mandrel
Mfr Part: E24

749-001-186WS
6mm (.241") Stainless Neck Turning Mandrel
Mfr Part: NTA24


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).

P.S. If you have a .223 do not use a Lyman type "M" expander and think the case will fit on your turning mandrel.
And always remember size matters.

 

[Uncle Ed]

I believe that the expander mandrel has a hole in one end and the turning mandrel does not, maybe????

The two different size Sinclair mandrels are marked on the top of the mandrel and the .243 mandrels are marked.
E24 = Is the expander mandrel at .242
T24 = Is the turning mandrel at .241

I use the Sinclair expander mandrel on the case necks before turning, this is because I polished my resizing dies expanders and the case necks can be a tight fit on the turning mandrel. Meaning the necks need to be .001 larger than the turning mandrel, and why Sinclair makes two mandrel sizes.

bored184, please send your check or money order to:
Uncle Ed wants a new rifle
PO Box 0000000001
Pennsyltucky 17112

 

[dreever]

Instructions For Sinclair Generation II Expander Dies
https://www.sinclairintl.com/userdocs/learn/Gen_II_Expander_Die_Inst.pdf

"Be sure to lube the inside of the case neck before running a piece of
brass over the mandrel. This can be done with a cotton swab or by
dipping the case mouth into the lube. We recommend using FP-10,
any of the sizing die waxes, or any sizing lube (Redding, RCBS,
Rooster, etc.)."

I use a needle oiler with FP-10 in it like below and put one or two drop on the mandrel.

FP10 is all I've ever used without a problem.

 

[Ledd Slinger]

I'm still stuck at the moment. Can't quite figure out how the OP was getting "copper" on the mandrel...

The answer is annealing. Doesnt matter if the cases are new. Might not have been done correctly at the factory. Anneal your case necks to 750 deg F and the problem will go away. I know new brass can be a pain to deal with sometimes. Just gotta work through it.

Also use a bronze cleaning brush for the inside of the necks before you plunge a mandrel in them. Dont twist, just a couple passes in and out usually works.

And don't "polish" your mandrel. That could make matters worse. A slightly rough finish will run smoother.

I've never once used lube on an expanding mandrel. Should never have to.