Max here has the best solution for you. The Lee Collet dies eliminate the expander altogether. To be honest, it's been about 2 years since I used a die I didn't make so I didn't really think to say anything about the lee dies. There is actually the most used commercially made die at the PA 1000 yd club. I made my own collet dies and was not real thrilled with the longevity of my brass but then they were my first attempt at making collet dies. I made mine from 416SS, collet and all.
Another thing I do is turn my necks on all my guns cases. I use two different methods for that also. My match gun's cases are all done in a CNC lathe. My hunting guns are done with a Sinclair or K&M Turning tool. I like the K&M Tool better but I have every mandrel for the Sinclar one so I use that one on the smaller cal guns. You can turn your necks down so that your die will close the opening just enough to get the bullet press fit you want. I go to about .0025 under. Now you may throw away the expander and don't need to worry about pulling on the necks of your cases. For instance, I use a 7mm expander for all my 30Cal cases. All I want to do is knock out the primer. Don't let that sucker touch anything.
Several companys sell carbide expander buttons for thier dies and you can get one of them also. They're about $20 if I remember right. I kinda prefer turning the necks and letting the die do its thing so I never bought one. Actually, I did ask one of the vendors at the range to bring me one, Then I asked again, and again, and after the 7th week I said screw it. I try to buy from the guys at the range but I'm just gonna go so far out of my way to give someone money.
The idea of "tuning" sounds pretty reasonable. I'm not going to try it as I don't have the problem any more but it sounds plausable that it would help.
For what it's worth, My swift dies are Lee Collet dies and just because my brother got a set of horrible out of round rcbs dies we decided to do a test. We chucked up the dies in the lathe and indicated the opening, then the neck area. The Lee dies were dead nuts on the money.
Let us know what helps You the most.
It is kinda funny, almost every time someone has a problem, My solution is to go buy something. I'm laughing as I type this but that's the general cure at the 1000yd club!
If you have something that you disassemble and reassemble enough times, sooner or later, you'll have two!
2) Get a die that uses neck bushings so you can control neck tension.
3) Turn your necks, if your necks do not have consistent wall thickness, they will not load concentric.
4) Measure wall thickness variance, once again if the wall thickness is off, once you shoot or size, the brass will not be concentric across its length. Cull the brass with large wall thickness variance. [img]images/icons/wink.gif[/img]
I've loved the Lee Collet dies since I first ran across them several years ago. But for what ever reason, I never did buy any for this rifle. I did buy a set of RCBS neck size dies. Big mistake. I've never seen dies give me worse run out.
Right now, I'm using the RCBS FL dies and Competition seater. I partially resize until the brass gets hard to chamber, then bump the shoulder back with the same FL die.
I did order the Redding bushing die and a .310 bushing the other night. I've been meaning to get one for better than a year, but for some reason I keep putting this rifle on the back burner. [img]images/icons/rolleyes.gif[/img]
If I can kill that coyote from here, Will you walk out to get him?
Jim Carstensen who advertises in Precision shooting and on the BR central board can convert regular dies to bushing and non expanding ball for $35. He does good work and quick turn around. He has converted several of my older Forster Bonanza BR dies to bushings. Price does not include the bushing. Lot of BR shooters use him for that work and he can make custom FL sizing die off your chamber reamer. He makes an undersized insert that is squeezed into the die blank. If you just ream a blank die with a chamber reamer you have no FL sizing! Resize reamers are undersize compared to the chamber reamer.
I did buy a set of RCBS neck size dies. Big mistake. I've never seen dies give me worse run out.
What was the runout "before" you neck sized?
The neck sizer will not hold the body tight like the FL die will, so consequently it will not correct any runout that already exists. Your FL die should, with out an expander produce near "perfect" cases and correct any runout problems in your brass from a bad chamber.
My 300 Ultra chambers neck area is eccentric in the order of + .005" at the 2 o'clock position so all I can do is FL size or index the cartridges to gain some consistancy. I mark the casehead at 3 O'clock and index the neck sized cases right now. I'm getting less than .005" runout way up on the bullets nose like this. I've not done a chamber cast to see if the neck or the body is lined up with the bore yet but one of them isn't.
With the Redding dies, which I still prefer, I've noticed the decapping stem will orbit the center and "never" be centered. If you leave the lock nut loose on top it will pull it closer to center as you draw the case neck back over the expander, but it isn't perfect. Redding dropped the ball with keeping their seating stems concentric. They are so far off it simply makes it impossible. Example, I use an RCBS Casemaster to check runout. if you take the seating stem out of the die, remove the decapping pin and collar, lay it in the supports, one one each end of the rod itself with the pin end to the left up against the stop and indicate off the flat just beneath the knurled head. There is always about .010" - .015" runout on the threaded adjustment head and it's only 1.0" in length at that point too. You can double that runout figure because the rod length is about that on the longer cases down to the expander ball. The rod is pressed in a bore that is not paralell for some reason or another, the threaded part is fine it's just the bore that holds the stem that is way off. If the threads on the adjuster are loose enough (lockring left loose), the expander will pull over close to center when with drawing the case but that's as good as it gets. The only way you can tune a stem to center up is to hope that the threads are unparalell also, causing the orbiting expander to intersect the bore centerline at some point. This is highly unlikely considering the threads always seem on center perfectly.
The carbide expanders are ball shaped almost and float on the stem with the hole in them larger than the stem itself, that coupled with leaving the lockring loose is the best way I've found to use the expander "if you must". I usually only use them to iron out dented necks if needed, I try to avoid using them. The smaller surface area on the carbide as well as it being harder usually doen't require lube, but if necks get harder or need to be opened up too much cause you die squeezes them down too far you'll still want lube, pressure to draw over the ball will tell you. I have had to use the ball on my Ultra with my neck bushing die because my bushing is too small now by about .003" which would leave me .006" tension and it takes some effort without lube but has not pulled necks up enough to cause tight headspace yet (3 times) using no lube. I get less than .001" runout using my FL dies.