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

[Webster]

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.

Galling can only happen with bad lubrication. A very tight fit makes it more likely with bad lube. If the mandrel gets real warm it's a sign of high fiction poor lube. I never had a problem. I only use oil. I put more oil on the mandrel after every couple cases. I have used 3 in 1 lube, motor oil and probably other stuff. Don't understand why people use anything besides oil. Every piece of machinery in the world is lubed with oil or grease. In my opinion these special products are made so they can be sold for high profit.

 

[dkhunt14]

Galling can only happen with bad lubrication. A very tight fit makes it more likely with bad lube. If the mandrel gets real warm it's a sign of high fiction poor lube. I never had a problem. I only use oil. I put more oil on the mandrel after every couple cases. I have used 3 in 1 lube, motor oil and probably other stuff. Don't understand why people use anything besides oil. Every piece of machinery in the world is lubed with oil or grease. In my opinion these special products are made so they can be sold for high profit.

He is not turning brass, only expanding it. If it is galling with Imperial wax, something is wrong. I have used it to turn and expand for years and done thousands of cases, never had it gall. Matt

 

[bored184]

This thread has been extremely helpful. I measured my mandrel after I polished it and I must of got a bit aggressive because the .242 mandrel is now .241. I switched over to a full length sizing die with a button for some and did not have any problems using imperial wax. After reading and reflecting I think my problem with the mandrel is two fold. I can not remember the ID of my necks but I do remember the necks being a bit tight, second a lube problem. The graphite was sticking nicely to the outside of the neck but not inside, when I switched over to the lyman case lube I may of been a bit to stringent in its use because I didn't want a lot of case lube in the brass.

More experimenting to come Saturday.

 

[Webster]

He is not turning brass, only expanding it. If it is galling with Imperial wax, something is wrong. I have used it to turn and expand for years and done thousands of cases, never had it gall. Matt

Sorry, old age creeping up. Same principals apply turning or expanding. If something is wrong better lube should cure the problem. Galling is caused by high contact pressure along with improper lube.

 

[Iowa Fox]

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.

Ackleyman, How are you waxing your bullets? Thanks

 

[AckleymanII]

Lee sizing wax in the tooth paste container

I use a one gallon plastic jug with a screw on top, wide mouth. Restaurants use this type of container that they receive condiments in.

Take the tube of lee wax, fill the first joint of your index finger full, smear along the insides of the jug. Now dump in 100 bullets or more. Screw on cap. Using a centrifuge motion, make the bullets move along the side walls of the jug, this will take about 1 minute max. Now dump the bullets out on a paper towel when the bullets look a solid milky color. Let the wax set up. If you want to use immediately, put the paper towel on a plate and place in the refrigerator. Wax will set up in 15 minutes or so.

You are done.

 

[mjl650]

Resurrecting an old thread..... exact same thing just happened to me as what happened to the OP. Did around 30 cases before discovering the problem, don't ask DUH!
What I want to know is what to do with the cases that have the scored necks? Are they still usable for anything other than foulers?

 

[JimSC]

What I want to know is what to do with the cases that have the scored necks? Are they still usable for anything other than foulers?

I would mark the cases with a sharpie on the head then load em and shoot them along with some that are not scored over a chrono and see if you can see any difference on paper or on the chrono.

 

[One Eye Pete]

For what its worth the best stuff I know of to prevent metal on metal galling is Zinc dialkyldithiophosphate, or ZDDP. (OK I did a cut and paste because I would never spell that correctly in a million years). ZDDP was the additive in motor oil that prevented metal on metal wear if the oil film broke down. That is untill the EPA got involved and greatly limited its use because they are afraid that it may harm catalytic converters after 100,000 miles. Todays motor oil contains very little. I do believe that STP still contains a fair amount. What does contain a good amount is engine break in oil, engine assembly lube and racing oil. Any of these would work well on a mandrel used for expanding or turning. What is also important is to make sure that both the mandrel and the inside of the case necks are coated. Just coating the mandrel alone may not be as effective because the lube will tend to be pushed away as it is forced into the case mouth.

 

[Webster]

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.

Petroleum oil has been the worlds universal lube on moving parts for over 100 years. I don't know why people think they need over priced stuff made for the purpose of making money. I live near Kelbly's and go to most of the Super Shoots. Almost all of the shooters use Imperial wax but they are using custom arbor press dies made to the dimensions of their fired cases. No mandrels. The more viscous the oil the thicker the protective oil layer thickness. For years I used a light vis synthetic oil which I got from work. Retired now. So I bought a qt. of petroleum oil based hydraulic fluid at AutoZone for $8. Been using it for years, no problem. Doesn't discolor he brass. I worked in research for a major oil company. The only problem with oil is a longer cleanup. I wipe the oil off of sized cases with a paper towel. About 8 cases per minute. If I am turning necks I put plenty of oil on the mandrel. I clean the neck i.d. with Q-tips soaked with acetone. Varmint rifle .250-.350" groups. Never liked putting Imperial on with my fingers seems like an uneven coating, but the worlds best shooters do it.