Hey Walter

[Brad]

Here is the die. I got as close to .431 as I could without going over. This is a bullet of range scrap air around BHn 12. I can get a little bigger but fear is going over. Alloy changes will make a difference, harder alloy likely springing back some to give larger bullets.

I need to make a push rod then will get it on the way to you.

 

[JWFilips]

Brad, I can see a precision tool business in your future
You make mighty fine tools....I love the ones I have!

 

[Ian]

The only hangup with a business is Brad would have to charge about $400 each for those dies in order to turn a profit.

 

[Brad]

And my current gig pays pretty damn well. Dealing with the public is a bit of a pain at times but the pay is too good to quit.

Actually Jim, I made a rule when I got the lathe. I don't want "for pay" jobs as it turns my hobby into a job. Hobbies are fun, jobs aren't.

 

[JSH]

Brad, what alloy did you use? I got some 12L14 to make lube dies.
Jeff

 

[Brad]

That is 12L14. I have made a few Star dies from O1 but just can't justify the added effort required to polish to desired size. If I was going to change to a different alloy I would likely go to 1144.

 

[fiver]

those are letters/numbers I didn't think I would ever see Brad type just a couple of years back.

your polishing and threads are getting better and better all the time.

 

[Brad]

I'm learning with threads. The new tool helped a bunch but I am also figuring out how to knock down the crests a bit so they aren't so sharp.
I will freely admit I still have a bunch to learn. The cutoff tool drives me nuts at times.
Some day I will get a mill and learn a whole new game.

 

[freebullet]

Some day I will get a mill and learn a whole new game.

And find out that freebullet moved into the space under the new work bench.

 

[JSH]

My tool and die maker was working for Lee Shaver a year or so back. They both agreed that the ease of working and finishing it would be a good alloy. I was concerned of it not being hard enough. They assured me it would hold up well. A lot of it is in the finish.

 

[Brad]

I wondered the same thing. What made me start changing my mind was how easy it is to polish a Lee sizer to a larger size. They certainly aren't made from tool steel!

Would be interesting to see a test on this. Maybe I should make a Star die for a size fiver uses a bunch and have him run 5-10K bullets thru and ask for a measurement on a few every K or so. Why fiver? Because he has a feeder for his Star and is better able to do this kind of run in a reasonable time frame. I bet he has 2.5-5 gallons of bullets waiting to be sized.

Oh fiver, are you interested?

 

[KeithB]

I would bet that if (a) the die has a smooth internal finish to start with and (b) the alloy used is grit-free, then you will get a little wear right at the start (probably less than .0001') and then little or no change after that for tens if not hundreds of thousands of bullets. What wears out draw/sizing dies is heat, high velocity, and abrasion from gritty particles. You don't have the first two problems sizing discrete pieces at hand-driven speeds (unlike the continuous machine drawing of wire for example) and you can control the third problem.

For the record, you can't quench harden 12L14, you can quench harden 1144 (called 'Stressproof" by a lot of people).

 

[Brad]

Thank you Keith. Information from a reliable source like that helps us a bunch. Always good to have some material science on hand!

I would hope that none of us has enough grit in our bullets to wear a size die. If we do the size die enlarging is good because the bore is soon going to need the larger bullets.

 

[KeithB]

By the way, a couple of good thread files make cleaning up threads as you cut them much easier. Each file has 8 different standard pitches on it, 2 files will cover almost any standard UN thread pitch you are likely to cut. They also come in metric sizes. Here are examples:

https://www.mscdirect.com/browse/tn...dsp=Thread+Restoring+File+Sets&navid=12106008

The first two files overlap in three UN sizes, the third example is metric. Further down the page is a metric file and then a set of four with both types featured. These, a good triangular needle file, and a clean cutting single cut flat file will greatly aid lathe threading. Use the flat file to knock the burr off the thread crest and the other files to clean up the flanks and chamfers.

 

[Brad]

I have been using a triangular file to clean up the threads followed by the same file used to push some 400 grit emery into the threads. It does a good job of cleaning up the little burrs threading creates. I just let the file find the start of the thread and follow it to the other end. Running the lathe very slow makes this a bit less scary.

I need to invest in some thread files to help speed the process.

 

[KeithB]

Thread files in the right pitch help at the start of the thread, makes it easy to clean up the chamfered end, and also to knock the burr off the top/crest of the thread. A flat file will push a little of the burr down into the thread flank, a V file pushes a little of the burr up to the crest, using both works well but a thread file knocks that burr off cleanly.

 

[Ian]

Being new to this too, I lightly file the OD with a flat file, then roll the burr back up with a triangle (or thread file, held backwards, with lathe in reverse to avoid crashing the shoulder if any), then Scotch Brite pad the fine burrs back off. Gotta work those burrs back and forth a time or two to get rid of them. Internal threads get taken care of with sandpaper and Scotch Brite because I haven't found a better way yet.