Pickin' the fly specs out of the pepper

B

Boyd Allen

Active member
Recently, I have posted that I have started using a Lee lock ring on my 6PPC sizing die. The other day, I happened to measure the runout of my sized cases, and it has improved a little. This prompted me to ask the following questions.

How many of you, who own lathes, have ever checked the lock rings that you use with your FL dies to see if the surface that tightens against the top of the press is true (perpendicular to) to the lock ring's threads? It would seem to me that a slight misalignment in this area would not be a good thing. With all of the fussing about straight, centered, and square in this sport, I find it curious that I have never read of anyone looking at lock rings to see if they are.
 
Boyd, after setting up my sizing or bump die to my press, I tighten the set screw on the lock ring..then remove the die and put it in the lathe (held on the die threads) and true the locking ring with very light cuts...I have had good results with this method of trueing my locking ring...




Eddie in Texas
 
Eddie

How do you know your jaws are true axially? The most accurate way would be to turn a stub with 7/8-14 threads and screw the lock ring on, secure it and then make a clean up cut on both sides. I say both sides because that eliminates one more mistake I could make. All this done in one setup.

Dave
 
Die Alignment

I know of several long range shooters who use flat washer between the lock ring and the press. I considered drilling and tapping my press and using a brass set screw eliminating the locking ring all together. I know other who use "O rings" and allow the die to flex and find its own alignment. John Widden makes floating die holders for Dillon progressive presses. There are two differing issues but both deal with die alignment.
Rustystud
 
Dave,
That is what I thought should be done.

Rustystud,
Years ago, I built a piece that fit in the primer feed notch of my Rock Chucker that has a deep narrow U that extends above the top of the press. I used it in conjunction with a lock ring of the set screw variety with a long screw that extended back through the sides of the U, with the lock ring high on the die, just above the press. Some dies worked better,some worse. I should retry it with a better fitting die and good brass.
 
Die concentricity

One has to wonder if the chamber in the die is dead center or not. If it is, you can put the die between centers. If you do this, you should make certain that the driving center in the chuck is turned down to a diameter that will go inside the die and center up on the neck portion. I would not trust the chamfer where the decapping pin assembly threads in. As always, you should set your compound and turn a point on the driving center to make certain it is true. You can check concentricity of the threads and square the nut. I probably didn't do well at explaining this, but I'm sure some of you understood.

Michael
 
micheal

Your suggestion seems like the most logical extension of trueing the lock rings except you have to face them off all the way to the bottom of the die thread. The dies are case hardened and it would take carbide and sparks would fly when you contacted the die body. This is one of those things you do the best you can and don't worry about the rest.

Dave
 
Dave Tooley...

Dave, you make a good point on the die body thread alignment...but when I trued the lock ring with the method I described I have tested the runout of my sized cases on my Sinclair runout fixture, and it was less that .001 on my guage that reads in .001" increments...
Maybe I lucked out with dies that are true to the threads..:D
 
Has anyone put an indicator on the face of the lock ring after the setup, before the cut? I am wondering how much correction was needed.
 
Facing the locking ring,,

If you lock the ring and face it then later have to adjust it again then you will have to re-face it again. You might even have to use a torque wrench as the 7/8 14 threads most likely will not be consistent due to wear and stress. The cheap Lee dies use to have a Lock Nut with an O ring built in. Unless your dies float like in a coaxial press you most likely are chasing your tail.
Rustystud
 
Dave Tooley said:
micheal

Your suggestion seems like the most logical extension of trueing the lock rings except you have to face them off all the way to the bottom of the die thread. The dies are case hardened and it would take carbide and sparks would fly when you contacted the die body. This is one of those things you do the best you can and don't worry about the rest.

Dave
Click to expand...

Dave,
I wouldn't cut that deep. I would cut it until I was right at the thread. Anything deeper than that does not contact the top of the press. Then you simply chuck the nut in the lathe and chamfer the inside that couldn't be reached. So this method in my mind is still the best after all.

Michael
 
Hi being new at this I have a couple of questions.

I see a lot of slop in the thread between the die and how it screws into the press. To remove this I put a spacer [ a dime, nickle, washer] on top of the shell holder run the ram to the top of the stroke, screw the die down snugly on the spacer hoping this aligns the die in the threads then lock a crossbolt lock ring into position. Is this better than using a rubber oring and let the die center it's self like I read in a article?

thanks

keep your tube warm :]
 
micheal

That makes sense. just out of curiosity what was the case runout before you worked on the lock ring?

While I've answered this thread I could have made 10 lock rings and know they were right. Drill, bore, thread, face and part off, face and part off again etc etc. I could make 5 in one setup. Sometimes the solutions are hidden in plain sight.

Dave
 
Dave Tooley said:
micheal

That makes sense. just out of curiosity what was the case runout before you worked on the lock ring?

While I've answered this thread I could have made 10 lock rings and know they were right. Drill, bore, thread, face and part off, face and part off again etc etc. I could make 5 in one setup. Sometimes the solutions are hidden in plain sight.

Dave
Click to expand...

Dave,
I've never trued my dies or checked them for run-out. As a tool and die maker, I was just trying to help others. If I was to do this, I would also want to square the top of the press and chase the threads true to the ram bore. Otherwise it's only half done. I think this falls into a catagory that I'll try when I get through chasing other accuracy details. When I think of all the details that can be done, and the amount of time it would take to try it all, I feel 10 years older already. I have found it to be more of a bullet and barrel game. My 30-30 shoots in the ones most of the time anyway.

Michael
 
Regardless of what you do with lock rings, if the 7/8-14 threads in
a press are not on a centerline axis with the ram, it will come back to haunt you. No different than an action with a perpindicular face and crooked threads, or an action with true threads and crooked face.
Currently I leave my die float, that is to say that it is not locked by a nut.
My only reason for this is because I use an adjustment system instead of shims.
Most lock rings are not real true, because of the way they are manufactured.I am pleased with Hornady rings, but actually I have found major improvements in
a set up that allows my shell holder to float.
Setting up a die in a lathe, to face off lock rings will work if you have a lot of luck, its more complicated than that. As Dave Tooley says, its
easier just to make good ones.
 
I have a Question

Anyone who has seen me at a Match could not help but notice those three rusty, crusty RCBS Partner Presses lined up on my loading table. But, they consistantly produce rounds that run out less than .001. There is a method to the madness.
Counting fly specs?? I guess we have already determined how many angels can dance on the head of a pin......jackie
 
Pbike

Go to a machine shop and tell them what you want, be sure to tell them perfect. When you get the bill, you will know why the 3.98 lock rings we use are off. That won't solve the problems. But a different approach might.
Read Jackies past posts on sizing cases
 
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