I need advice on my neckturning method. Maybe.

R

Roy Allain

Guest
I have 2 K&M turners for my 6ppc.

After expanding with the K&M expander, I use their carbide mandrel to cut down to .0010 neck wall. It gets a bit warm, but I cool in air from a blower.

Then I use the regular mandrel on another cutter to cut down to .0084. This second cutting gets very hot real quick and very hard to pull out of the neck.

Am I doing something wrong? Or should I just reduce the OD of the 2nd manrel about .001?

I use Imperial wax on the mandrels. My cuts are accurate and very smooth. All would be perfect except the heat and the tight mandrel.

Any suggestions?
 
Go veeeeery slooooow. Let the cutter pull the brass in. I also use two K&M turners and never have a heat problem. I take the majority off with the first one and finish up with the second one. Pushing the case hard into the cutter, with the intent of speeding up the process, will create a lot of friction and generate heat quickly. I believe going slow is the key. When I run the case necks through the expander I do it four times. Each time I make a quarter turn with the case. Too much work? I don't think so. I'm looking for uniformity and expansion that's spot on with the expander. Just one of my idiosyncrasies. ;)
 
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I keep my cutter in ice water while I exchange the cases into the holder. I only expand 5 cases at a time and then turn them. I don't do the 2nd cutting of a case until I have expanded it again. I turn at a pretty decent speed, in the neighborhood of 200-500 rpm. The ice water keeps the cutter at a constant temp each time while the brass is at room temp (65-68 degrees). I use imperial die wax while expanding and also again when cutting. You may wnat to measure your expander against your cutter mandrel. I believe they should be about .001 difference between them. Randy J.
 
I think I should elaborate a bit.

I expanded the new brass together. About 60 pcs.

Then I usually turn 10 at a time. I cut all 10 pcs. to .0010 with the carbide mandrel turner. Then I turn them again with the other turner with the steel mandrel. The 2nd turning is where I have most of the heat problem and difficulty moving the mandrel out of the neck.

On the 1st turning, I usually go in and out pretty fast.

The 2nd turning is much slower going in and very slow out. The mandrel usually goes in easy, but is very tight coming out and VERY hot. The heat obviously expands the mandrel which makes for a tight fit.

I normally air cool the turner after each case, but I can't say if the mandrel is cool enough internally.

I've been through this a couple of times with Ken Marklel over 5 years ago. I've bought 2 additional mandrels but I still have the same heat and hard removing of the 2nd mandrel.

After reading these replys and an old post from 2008, I think it might be that the expanding mandrel is not really oversize. I can't say what it actually is, but I'll put my Starrett mike to work tonight and let you know what I find.

Perhaps that may be the problem. If so, I'll need some more advice on how to remove enough, but not too much metal off the expanding mandrel.

Sorry for the long post.

Roy

P.S: Good to be back on the forum. Katrina kicked the crap out of me and I stopped shooting for over a year.
 
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Whoa Roy!

Don't take metal off the expander. It would be the cutter mandrel that may be too large if anything. Have you tried to expand it again before using the second cutter? Randy J.
 
I keep the turner in a water bath. Room temp water in a bowl.

I use a lube like STP or Power Plus or 90wt gear oil or my current fave "assembly lube" which stuff is designed to be put on and STAY on while assembling parts. I keep a thin layer on a flat surface (the lid) and dip the tip of the neck.

I've not had good results using die wax. I think this is important.

IMO going veeeeery slooooow doesn't help anything. Your feed and speed should be such that the thing gets done before it's hot.

I believe that the mandrel expands. I regrind my cutters and they cut both ways. Heavy cut in, very light finish cut out. The necks shine like mirrors. In a perfect world, while turning 6MM, my mandrel heats up to "body temp?? 120degrees??" (It's warm to the finger...)

Good to see you Roy :)

al
 
I agree with Al, I don't think sizing wax is an appropriate lube/cutting oil.

Part 2: Once you have prepped some .269 neck brass you will not go back to .262. Slow in, slow out, done.
 
German Salazar said:
Al, how do you remove the lube you use? I'd like to move beyond Imperial but worry about chemical residue affecting primers. You must have this problem licked, any advice would be appreciated. Thanks.
Click to expand...


Wellll, NO I don't have this problem licked! :)

It SUUCKS....... But for me there's always a fireform round or two before firing for effect so I gener'ly don't have to worry.

I use Q-tips to reach in and pull out the bulk stuff.

I use a 0000-wrapped brush to polish inside the neck and I sometimes go so far as to run an air hose into every case. This is mainly for those rounds which require inside neck reaming, rounds with CRUD in them, chunks.

I've washed in soapy water.

I've got tumblers and vibrators and an ultrasonic cleaner.......

Generally now I just clean them up well enough by wiping that the powder doesn't hang up in the necks and FIRE THEM! :rolleyes: After fireform I go through the whole mess again anyway inspecting and weighing and lurking into the various corners and orifices.....I haven't found any residue to speak of, certainly nuttin' that would taint a primer. Now, I wouldn't do ANYTHING along the lines of case prep on pre-primed brass! I'm pretty anal about my priming, the care and keeping thereof. If you're talking primed brass, dunno.

And after all this, when I drop a case on the floor I CRY :(

Really......

al
 
BTW......


All of this is why I shoot disciplines where I can make my cases last forevermore EVER!!!

I'm firmly convinced that if you're gonna' make cases you might as well make GOOD cases, and then keep them. I can't AFFORD to make GOOD cases that only last 5-10rds! My cases last 50-rds.....a hunnerd rounds...... I don't even KNOW how many rounds, basically until I screw up! My attrition comes from misuse and abuse, not from USE...

German, I'd go mad shooting XC and the like. I'd spend twice't as much on the gun/reamers/fittage etc so that I could quickly and easily make brand new cases work "like fitted brass"........ I'd short-chamber so short that I'd have to gently reset every shoulder for fit.

And I wouldn't even MESS WITH neck turning!

A "Short-Fat Factory Tight Neck"......:)

LOL

al
 
Al ...

alinwa said:
Wellll, NO I don't have this problem licked! :)

It SUUCKS....... But for me there's always a fireform round or two before firing for effect so I gener'ly don't have to worry.

I use Q-tips to reach in and pull out the bulk stuff.

I use a 0000-wrapped brush to polish inside the neck and I sometimes go so far as to run an air hose into every case. This is mainly for those rounds which require inside neck reaming, rounds with CRUD in them, chunks.

I've washed in soapy water.

I've got tumblers and vibrators and an ultrasonic cleaner.......

Generally now I just clean them up well enough by wiping that the powder doesn't hang up in the necks and FIRE THEM! :rolleyes: After fireform I go through the whole mess again anyway inspecting and weighing and lurking into the various corners and orifices.....I haven't found any residue to speak of, certainly nuttin' that would taint a primer. Now, I wouldn't do ANYTHING along the lines of case prep on pre-primed brass! I'm pretty anal about my priming, the care and keeping thereof. If you're talking primed brass, dunno.

And after all this, when I drop a case on the floor I CRY :(

Really......

al
Click to expand...

Sounds like a straightforward task has turned into a chore. I must being doing something really wrong because it has only been an enjoyable and nothing-to-it experience for me !!! ;)
 
Your loss.

alinwa said:
BTW......


All of this is why I shoot disciplines where I can make my cases last forevermore EVER!!!

I'm firmly convinced that if you're gonna' make cases you might as well make GOOD cases, and then keep them. I can't AFFORD to make GOOD cases that only last 5-10rds! My cases last 50-rds.....a hunnerd rounds...... I don't even KNOW how many rounds, basically until I screw up! My attrition comes from misuse and abuse, not from USE...

German, I'd go mad shooting XC and the like. I'd spend twice't as much on the gun/reamers/fittage etc so that I could quickly and easily make brand new cases work "like fitted brass"........ I'd short-chamber so short that I'd have to gently reset every shoulder for fit.

And I wouldn't even MESS WITH neck turning!

A "Short-Fat Factory Tight Neck"......:)

LOL

al
Click to expand...

If you would just take a bit of time to clean your cases afterturning w/ lacquer thinner or acetone, you would find there is not a problem later.

If you enjoy the disciplines you are shooting, keep it up. If you lust for the TRUE accuracy, take a bit of time to be consistannt and shoot point bl;ank BR. The true ACCURACY comes from taking the time to do whatever it takes to get the ULTIMATE out of your rifle. No Matter What!!!
 
Glad to be back here, ya'll

Katrina really messed with my head, big time. I didn't care about anything, didn't want to do anything. But I'm much better now.:eek::D
 
Imperial sizing wax

crb said:
I agree with Al, I don't think sizing wax is an appropriate lube/cutting oil.

Part 2: Once you have prepped some .269 neck brass you will not go back to .262. Slow in, slow out, done.
Click to expand...

K&M sorta don't agree with that. They said to use sizing wax and on the 2nd turning use a thin lube like detergent cutting oil.

Didn't work to well. Still got real hot.

See later post.
 
Roy: I make turning mandrels in .0005 diameter increments to get the best fit on an expanded neck. Now, if the expander mandrel is only .001 over your turning mandrel, it's going to be pretty tight...hence the heat.

The biggest problem I see people running into is trying to run minimum clearance between neck i.d. and the mandrel o.d. That's why I make my own mandrels..so I can juggle.

I like a 50/50 mix of STP and Mobil One 5w20 for turning. When the cases are done, I toss 'em into a small plastic bucket filled with acetone and scrub the beejeezus out of the insides with a .45 cal brush on an RCBS handle. They're dry inside within 20 minutes and need no further drying/swabbing inside the cases.

Lots of ways to do it..this works for me. :)

P.S. Gloves on with the acetone....or you'll hands will look like Michael Jackson's face. :D
 
Measurement results

Promised mandrel measurements follow up

My K&M Expander Mandrel measures - .2432

My K&M Carbide Turner Mandrel measures - .2420 -- .0012 undersize
My K&M Tool Steel Turner Mandrel measures - .2416 -- .0016 undersize

The expander mandrel is sufficiently oversize, so that isn’t the problem.
It is apparently heat buildup in the tool steel mandrel causing it to expand and brass springback.

After reading your posts and interpreting the measurements, I decided to expand a piece of new brass and then turn the neck to .010. Then expand again and turn to .0084.

Or at least do that to 1 or 2 pieces and see what happens. Does this seem correct, so far?

Thanks for all the advice. Keep it up Al, you’re a real gas.

Roy
 
Roy; keep in mind that even though the expander mandrel measures .0012 over the turning mandrel, the necks 'snap back' smaller than what the expander mandrel measures. A .001-.0015 'snap back' is not uncommon.....depending on annealing, etc.

The brass is just trying to do what it's supposed to do....get back to it's original dimension.
 
German Salazar said:
Maybe a good acetone wash and then leave the brass out in the AZ sunshine to bake out whatever is left in there for a few days. Time to do some head scratching and soul searching (and navel gazing). Thanks!
Click to expand...

German: it won't take that long for them to dry...20 minutes, tops if you scrub the insides with a brush. I've done hundreds of cases this way and it's a real time saver.

A gallon of acetone is about $10 here. But don't pick up 20-30 individual gallons, ask for a volume discount or inquire about the industrial sized 55 gallon barrels, though. ;) They'll have you pegged as meth cooker, for sure. And before you know it, you'll be starring in the real-world version of 'Breaking Bad'. :eek: :D
 
Hey Roy, Katrina kicked lots of people's butts, for sure. Glad you are recovering, that was a tough lick. I spent six weeks in and around New Orleans, after Katrina and Rita, was afraid my wife and cat would forget who i was. I don't know if this is correct, but when i turn case necks, i only remove about .003 with each cut, i use a light wt oil like FP10, or tap magic, and i degrease them with spray electrical contact cleaner, sprayed on heavy and stood up to dry in a loading block. Lots of good ideas, here. Good Shooting, Lightman
 
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