A tale of Two Dies --- What's happening?

[amlevin]

Two .308 Win dies from two good companies, different results.

I have two sizing dies, one Forster BR F/L sizing die and the other a Redding F/L Sizing die.

Mounted in the same press, using the same LNL Quick Change adaptors, I get two widely different results, even when sizing the same case.

When sizing a fired case in the Forster die runout at the center of the neck is less than .0005" Size another case using he Redding die, in the same press, and it yields runout of .003" - .004". I can then change dies, resize the high runout case in The Forster, and Bingo, less than .001", every time. If I take one of the "near zero" runout cases I've sized in the Forster, then size it again in the Redding, "Boing", it's back up to the .003" - .004".

I've tried this with the dies solidly mounted and locked down with lock rings, no o-rings, and I've used them in the Hornady LNL QD bushings which have an o-ring to allow for some self alignment. Is it possible that I have a Redding die that is that far out of round?

I'm interest to see if others have had problems like this. I know, I know, "Just use the Forster Die, right?" That is certainly an option but I want to use the Redding die on my XL-650 as it has the carbide expander ball (floating) and it will simplify loading on the progressive. I'd just like to make sure I get some reasonably straight .308 rounds.

 

[BoydAllen]

I take it that both are one piece, non-bushing dies. Is there a difference in the resistance that you feel when you pull the expander back through the neck? Are you lubing the inside of the neck for one and not the other? If you size a case in each, without the expanders in place what is the result as to straightness and neck diameter? One difference between the designs is that the Forster expander is mounted high, so that the neck is partially in the neck portion of the die as the expanding is starting at the base of the neck.

 

[Gene66]

I had the same problems with Redding F/L dies in 260.I sent back to Redding 8 weeks later they sent it back, same problem runout .004 to .005
I now have a Forster F/L die runout .000 to .001
Good Shooting
Gene

 

[amlevin]

I take it that both are one piece, non-bushing dies. Is there a difference in the resistance that you feel when you pull the expander back through the neck? Are you lubing the inside of the neck for one and not the other? If you size a case in each, without the expanders in place what is the result as to straightness and neck diameter? One difference between the designs is that the Forster expander is mounted high, so that the neck is partially in the neck portion of the die as the expanding is starting at the base of the neck.

I haven't checked the dies without the expander ball in place. No need to with the Forster and I didn't see the need on the Redding as the carbide expander ball "floats" on the de-priming stem. It "should" self align.

I'll try the Redding without the expander and stem installed. If I get the same results I'll start the "back and forth game with Redding -------------- Or just buy another Forster.

 

[BoydAllen]

The reason I asked for both without the expander is to make a comparison, not to diagnose a die that works.

 

[sailhertoo]

Let us know how it goes with out the expander ball.

 

[Dimwit Flathead]

You may discover that even a "crappy" die does pretty well with the expander removed. I really believe th

 

[amlevin]

Well, I tried it with the expander removed and the outside of the case neck now shows the same run-out as the Forster sized cases.

Now to figure out why the floating expander ball is making them crooked. Even measured case neck wall thickness for variations and all were within +/- .0005"

 

[BoydAllen]

What I was trying to get a look at, when I asked for the neck ODs of cases from both dies, sized with expanders removed, was the amount of expanding up that is being done by each dies expander. Years ago, I figured out that when the ID of the neck portion of a one piece die is smaller than it needs to be, and the expander has to make excessive diameter change of the neck, that the pull created, can exceed the yield strength of the brass at the shoulder and that it will give asymmetrically, cocking the neck. I believe that this may be the case with your Redding die, and I was trying to conform this from actual dimensions by asking for the measurements. I guess that I should have explained why I wanted them. There are other things that could have caused your problem, but since your unexpanded case is straight, this is likely to be it. Again, what are the ODs of your sized without expander necks from each die?

 

[bugman]

Another option to consider....Is the stem centered to the case or angled to any degree? Even a floating, titanium ball can introduce runout if the stem is not properly oriented.


Jack

 

[mikecr]

The runout from the Redding is your brass thickness variance pushed outward by the expander. Apparently you have no expansion happening with the forster.
What matters is loaded runout as measured off bullets. Here you're as likely to find the Redding is doing a better job.

 

[bigedp51]

After reading the link below could there be a difference in the neck diameter of your dies or diameter of the expander buttons?

Reloading: Two-Step Sizing and Concentricity
http://riflemansjournal.blogspot.com/2010/04/reloading-two-step-sizing-and.html

 

[BoydAllen]

I doubt that he has .003 to .004 variation in neck clearance thickness. Reread my last post. It is not some guess. I proved it years ago, by experimentation and careful measurement. Unfortunately there are many who have not done that work. Another way to make a bad dies results better is to use it without the expander and expand as a second step with an expander die and mandrel, with lube of course. In the case of a die with too small of a neck ID, this will give smaller runout than using the die's expander. Again, this has been confirmed by actual test with a significant number of cases.

 

[amlevin]

Not wanting to just toss this die in the "forget about it box" I did some more playing around.

This morning I sized a case or two with the lock ring on the de-priming stem loose. Not just "loose" but backed off a couple of turns. There's enough thread slop to let the stem float a good 1/32" in any direction.

The cases sized were now equal to what I was getting from the Forster Die. The de-priming stem in the Redding die is extremely stout and has no flex. I noticed that the de-priming pin would be forced off center (visually) when I tightened the lock ring on the stem.

Boyd-

The expander ball is expanding he brass about .003" when I check first with the expander out and then size the same case with the ball "in".

Leaving the stem sloppy loose has made all the difference in the world. I think I'll just wrap a couple of rubber bands aound the threads above the die and run the lock ring down to the bands just to keep the stem from backing out to the point it won't de-prime the cases. I guess I could, if I wanted it to look professional, put a nice thick o-ring on the threads instead. I don't know though, rubber bands look so "unique" 8) Might even just use some "Tactical Duck Tape" : : (you know, Black instead of Gray)

 

[amlevin]

The runout from the Redding is your brass thickness variance pushed outward by the expander. Apparently you have no expansion happening with the forster.
What matters is loaded runout as measured off bullets. Here you're as likely to find the Redding is doing a better job.

All the cases I'm sizing have been neck turned and even after numerous firings show <.0005" of neck thickness variation.

Sorry, but even after this mornings experimentation, the Forster's still doing the better job. Leaving the stem loose in the Redding just makes it do a better job.

And yes, the cases still read the same after a bullet is seated. The straight ones from the Forster are still straight after I seat bullets and the crooked ones from the Redding die didn't straighten out when the bullet was added.

 

[BoydAllen]

Thanks for the follow up. Although I seldom use one piece dies with expanders, I learned something. I will have to give it a try the next time that I am forced to use one.

 

[jsthntn247]

I use them one piece dies and expanders in some of my hunting guns and went to Home Depot and got rubber washers. A small one where the decapping pin screws in and a bigger one where the die screws in to the press has helped.

 

[amlevin]

I use them one piece dies and expanders in some of my hunting guns and went to Home Depot and got rubber washers. A small one where the decapping pin screws in and a bigger one where the die screws in to the press has helped.

I have a smaller version of "Home Depot". It's called a "kitchen drawer". I actually found an o-ring under all the accumulated junk that fit between the lock ring on the de-priming stem perfectly. The right ID and OD.

I pointed this out to my wife who's always telling me to clean out the drawer. I took the opportunity to point out how much time, money, gas, and aggravation, that this "drawer" saved me

As for an O-ring or rubber washer under the die lock nut, I've installed a Hornady LnL bushing kit in my new RCBS press. All my dies are now set up in a Quick Change Bushing which has an o-ring installed. The die is just loose enough to align with the axis of he case. Just to make sure that the OAL's and headspacing remain the same I have "index marks" on both bushing and press/adapter.

FWIW, I do like the floating carbide ball a lot. I no longer lube the inside of the case necks. No chatter or extra drag. The carbide expander ball is polished to a mirror surface.

 

[58weasel]

Have a Redding FL bushing die for 284W that appears to have too long of a chamber on it which would prevent any setting back of the case's shoulder. Also without the bushing in the die, and looking through the die you see not a circle but three arcs with tangent lines between them. Putting new Lapua brass (6.5-284) into the thing engraves the top of the shoulder with the three arcs, which together seem helical in nature (like a bolt thread). No wonder the die was on sale at Midway.
Anyone else having quality control problems with Redding?

 

[amlevin]

Thanks for the follow up. Although I seldom use one piece dies with expanders, I learned something. I will have to give it a try the next time that I am forced to use one.

I quit using them for a while but when I went to F/L sizing I didn't have a F/L bushing die.

I figured that the F/L die owned should work better than it did. Now it does.