Full Length Die Concentricity Question--Any Caliber

[killdeernow]

Please be patient with me…alright, here we go. As some of you might know, I’m sort of a novice at reloading. I’ve conquered the 223 WSSM so I figured that was a major milestone for me heading to the next level of reloading. But the issue I need help with has set me back…I think. I’m using this forum because it seems like there’s a more intelligent/experienced crowd here that reloads (no pressure intended).

What we have below is a Redding 264 Winchester Magnum full length sizing die. All the pieces are dissembled (hex nut for lock screw is threaded but sticking out (I’ll lose it if I take it apart)).



Now, here’s the decapping pin/expander button assembly (help me w/the terminology if I’m screwing it up), assembled. Pretty easy stuff so far.



Next I assembled the decapping pin/expander button assembly into the die body (again, terminology?). Still pretty easy stuff.



Now comes the interesting part, so I think. It might be “normal” but it will take some convincing as to why. When I screw the decapping pin/expander button assembly into the die body (looking into the die body) it is oblong (not concentric) when you are screwing it in (you can see a still shot here and w/the human eye tell it’s not concentric).



In other words, the decapping pin/expander button is not concentric to it the die body when it is being screwed in. A matter of fact, you can wiggle the decapping pin/expander button assembly until you tighten down the lock nut. Is that normal? I found this picture online that captures my issue perfectly. When you are screwing down the decapping pin/expander button assembly it does what the bottom part of the diagram depicts.



Does the lock nut ensure concentricity when it’s tightened (top part of picture)? If so, how do I know?

Can you guys do me a quick favor and grab a few of your full length sizing dies and see if yours do the same thing? I’m thinking with all the “precision” talk about shooting, reloading, etc that this is something that needs to be addressed. My 223 WSSM Forster die does the same thing. I just never noticed it until went back to see.

Thoughts?

And BTW, thanks. You guys give awesome support/advice.

 

[DrMike]

By the way, you are to be congratulated for an excellent question--clear and concise. By the nature of the design, all dies are somewhat eccentric. They are, however, somewhat self-centering as the ram is raised. The case has some limited movement in the shell holder (with the possible exception of the Forster Co-Ax press and/or an Arbor press). Likewise, the spindle (or stem) moves as it enters the case neck. Together, a consistent technique accomplishes concentricity for the resized case.

 

[Oldtrader3]

I have found more effect on concentricity being related to the expander plug design being used and the force required to resize the neck. I always use either a Redding or Forster Carbide expander button for neck resizing. The much lower lever force required to size the case mouth also seems to contribute better TIR (run out) for the case neck. Also the Redding buttons are spherically tapered and seem to align the case necks much better with much less trauma to the necks (unlubricated). Plus these expander plug shafts are straighter, the buttons more concentric and seem to just work better all around.

 

[FOTIS]

Doc Mike nailed it

 

[DrMike]

I have found more effect on concentricity being related to the expander plug design being used and the force required to resize the neck. I always use either a Redding or Forster Carbide expander button for neck resizing. The much lower lever force required to size the case mouth also seems to contribute better TIR (run out) for the case neck. Also the Redding buttons are spherically tapered and seem to align the case necks much better with much less trauma to the necks (unlubricated). Plus these expander plug shafts are straighter, the buttons more concentric and seem to just work better all around.

+1, Charlie. All my Redding dies have carbide buttons.

 

[Kodiak]

All the above works best when the inside case-neck is also clean, as in no powder residue build-up.

 

[rick smith]

I very seldom use expander balls, steel or carbide, preferring to use bushing neck dies. But on the die sets where I have to use an expander ball, I polish the expander to a mirror finish and use a dry lube inside the case neck. If you want the expander ball to be concentric in the die, raise a case fully into the sizing die, as you remove the case and it makes contact with the expander ball tighten the expander assembly on the top of the die.Rick.

 

[Oldtrader3]

Forster dies locate the expander ball just below the neck sizing cavity, so that the ball sizes the neck while the upper outside diameter of the case neck forming is still inside the neck sizing die. Thus assuring better alignment between the die and the expander ball.

 

[ElmerThud]

I very seldom use expander balls, steel or carbide, preferring to use bushing neck dies. But on the die sets where I have to use an expander ball, I polish the expander to a mirror finish and use a dry lube inside the case neck. If you want the expander ball to be concentric in the die, raise a case fully into the sizing die, as you remove the case and it makes contact with the expander ball tighten the expander assembly on the top of the die.Rick.

+ 1 on the above. ATB ET

 

[ElmerThud]

I very seldom use expander balls, steel or carbide, preferring to use bushing neck dies. But on the die sets where I have to use an expander ball, I polish the expander to a mirror finish and use a dry lube inside the case neck. If you want the expander ball to be concentric in the die, raise a case fully into the sizing die, as you remove the case and it makes contact with the expander ball tighten the expander assembly on the top of the die.Rick.

+ 1 on the above.
I don't go to the extra trouble of polishing, but set my FL sizing die, then using a lubed case, loosen the de-cap rod, then send the case into the die. As soon as the expander ball enters the case neck & the tension felt, tighten the lock nut on the de-cap/expander rod.

Incidentally, when setting the FL sizing die, I like to have a rubber O ring under the die locknut and initially because the shellholder may not be machined 'square' when the die is resting on top of the shellholder with the ram up, slight pressure to move the die 'upward' to the top of the coarse thread, is where I square off and lock down.
Doing this helps with die concentricity to shellholder and helps the case self centre in the shellholder too. (I only think that, I can't tell exactly if it does)
The rubber O ring then gives me enough movement screwing the die further in/out to help get very accurate headspacing.
To achieve this, an exact marked datum point should be made on both die & press.

This procedure has for me helped produce accurate & consistent ammunition.

Rob, you neatly identified & precisely described a hidden trouble spot.
ATB ET

 

[Guest]

I will only add that I've seen similar issues with Redding dies, moreso than other brands. I've all but stopped using them because of various simple QC issues I've experienced which have all been concentricity related. I have one remaining set, and when I can afford to replace them, I will. In the meantime, I'm very careful with those Redding dies, as they just aren't up to snuff in my opinion.

I know folks love Redding, and Redding is supposed to be the bee's knees as far as quality (right behind Forster) but my experience with their products has been disappointing across the board. Unless forced, I won't use them.

 

[Guy Miner]

Interesting discussion, and reminds me of why I went with Wilson dies, which have no expander ball, for my rifles I expect the most accuracy from.

Guy

 

[kraky]

Another +1 for getting that stem to the middle of the die...and its probably impossible to get one perfectly centered.
Ricks method of having a shell hold it while tightening works.
You can also "walk it" towards the middle by making small 1/10 turns under slight tension.
Size a few brass and check run out...if good tighten down.
If not make another bit of turn...repeat and you will eventually hit a sweetspot.
Re Forster dies...the seating die is mostly what makes them good...although having the ball high in the sizer keeps it closer to center.
I'm moving more and more to using a redding body die and lee collect w/mandrel polished down .002".
But a good seater still completes this idea.

 

[balew6254]

I leave the lock ring slightly loose on the expander/decapper rod. Haven't had any problems yet and my loads shoots pretty well. Thinking about this, I will try an o ring under the lock washer to keep the lock ring from moving and see if that still allows the rod to float enough to self center. I probably need to invest in a tool to measure neck runout, but don't see the bullet tips off center much when I roll them on a flat surface. Here is the usual disclaimer, YMMV.

Bruce

 

[killdeernow]

Wow, all the above is great advice. Mike/ElmerThud, thanks for the shout-out for describing an issue in detail. I try to be as non-ambiguous as possible when confronted w/an issue that I need help with.

So, my conclusions are plentiful: 1) it’s a known problem that sort of corrects itself due to the “play” in the reloading equipment as a whole (paraphrasing here) 2) cleaning the neck is a must 3) dry lube in the neck is recommended 4) carbide is favored over steel 5) loosen the decapping pin/expander button assembly, raise the casing until you feel tension then tighten the decapping pin/expander button assembly or 6) "walk it" towards the middle by making small 1/10 turns under slight tension and 7) use an o ring under the lock washer to keep the lock ring from moving

I will say I like Forster as well. However, Forster does not make 264 Win Mag dies. I emailed them and asked if it was in the making. I received an immediate email back but the answer was no and it’s not on the horizon either.

You guys never disappoint…I don’t say much in terms of posts but I’m probably the biggest lurker in this forum (read mostly everything w/out logging in). Thanks again,

 

[ElmerThud]

Even after many years reloading Rob it's easy to forget the stuff learned years ago. But there are new ways of thinking emerging all the time and site's such as this are excellent advice/info forums.
Your clear identification of an unseen factor possibly affecting performance of reloaded ammunition, is an issue and should be taken into account by all those seeking the best achievable performance, particularly by those using ordinary dies.

While I'm not rushing out to buy a concentricity guage, & even if I had one, would certainly not for my uses of my rifles, re-make any round found to exceed the 'norm'. The way to go is in my view, to assume every round might exceed desirable run-out & make every round to begin with, as 'perfect' as possible. (Of course, you'll never know if you succeeded until the round is fired) But there's a better than good chance you did, if you're careful.

So, for me, small 'tips' & 'techniques' that will help me achieve a good average standard of accuracy on the range and in the field, as far as possible eliminating 'flyers' that are not of my own actual shooting deficiency, is a must. Just because I want it that way.

I believe while I don't use 'top-flight' bench rest dies, I use decent dies (RCBS F/L & N/S + RCBS Comp. seating dies) with added help i.e. info from manuals, up to date knowledge & the lads here, excellent consistency of reloaded ammunition can easily been achieved.
It just need some care in case prep., setting up sizing dies and added technique for bullet seating.
ATB ET

 

[ElmerThud]

I came across this article while I was looking into whether or not to change my bullet seating dies. Maybe some of you will enjoy reading it. Cheers, ATB ET

http://riflemansjournal.blogspot.co.uk/ ... unout.html

 

[DrMike]

Most interesting article, ET. The only surprise to me is that the Wilson produced ammunition that measured greater runout than does the Redding. Still, all were pretty good, which should comfort hunters.

 

[kraky]

I had seen that article before and it does NOT mirror my experiences loading ammo w/FL dies and i believe this is why.
If my calcs are right he set up for. 002 neck tension.
Its been my experience that a lot of FL dies leave. 0035- .004 tension.
I've seen wsm brass spring back to .007 w/a caliber diameter expander.
Bullets tend to seat real ez w/ just .002 case mouth grip and definately stay on line in the brass when doing so.
I've come to believe for higher recoiling hunting rounds I need more than .002 tension to seat into. Others may disagree but its what 20 yrs of reloading has shown me.
Bottom line for me is he is correct for light tension bench shooting seating dies are pretty consistant a cross the board but big differences will show up as neck tension increases.

 

[ElmerThud]

I came across the article while thinking of whether or not to use different seating dies other than my Comp RCBS, this in an effort to ensure as little run out as possible if another manufacturers dies could ensure it. I came to the conclusion that for my purposes, my RCBS comp seating die was just fine. Although, I might well give a Forster Ultra seating die a go, if I can find one to borrow.

The author has done his test, fairly comprehensively with what was available to him and those are his findings. I would not dispute his results, but they aren't specific to my requirement so I neither agree, nor disagree as I haven't done my own individual test and probably never will.

However, the test structure he ran did provide an interesting outcome. ATB ET