308 Concentricity Issue....possibly seating die?

[farmergreg]

Loading WIN 308 brass, the MAJORITY of my loads are coming out at .004+ TIR.
Measured by 21st century fixture & Mitutoyo indicator

Method:
Forster Co-Ax press
2X fired brass from my chamber = Checks at .0005-.0015 TIR
LEE Collet necksized .0015 under = Checks at .0005-.0015 TIR

Micrometer seating die = gets interesting! Majority at .004 up to .008 TIR
(I also tried another die lock ring on the thought that the original might out of spec)

I disassembled Seater die.
And measured the "sleeve" that supports the brass and guides the bullet finding the following:
.0004 TIR outside diameter
.0035 TIR inside diameter (where base of brass would contact)
.008 TIR inside diameter where the bullet/seater stem goes through

I've haven't run into this before, but believe I'm on the right track.
1. Most TIR is being introduced by the seater.
2. The tolorance on the "sleeve" is very loose. (By my thoughts)

Has anyone ran into this issue? It this "sleeve" typically machined to these tolerances?
Should I contact the die manufacturer?
(I don't want to publicly bash the MFG so I won't mention names)

 

[Homerange]

Are you doing a double bump with the collet die with a 90 - 180 degree turn between bumps ?
Many do this and it's been known to improve runout.

 

[farmergreg]

Are you doing a double bump with the collet die with a 90 - 180 degree turn between bumps ?
Many do this and it's been known to improve runout.

I haven't been doing that. The collet hasn't been inducing the run out.

 

[Patch700]

My advice... if you do not own the reamer used to chamber your rifle , is to send that sleeve and a sized case to your smith and tell him to make chicken salad out of chicken $hit lol.. Or if you have the reamer , then shorten it (the sliding sleave) off the bottom about .020" and run your reamer into it.

If that don't fix it , send it back.. Or give em a call monday and tell them your findings.

Good luck

 

[ireload2]

You cannot fix that sleeve.
If you are confident of your run out measurements contact the manufacturer and expect that you will have to send it back for a replacement.
It is not bashing if you are correct. You are merely stating fact.

 

[farmergreg]

My advice... if you do not own the reamer used to chamber your rifle , is to send that sleeve and a sized case to your smith and tell him to make chicken salad out of chicken $hit lol.. Or if you have the reamer , then shorten it (the sliding sleave) off the bottom about .020" and run your reamer into it.

If that don't fix it , send it back.. Or give em a call monday and tell them your findings.

Good luck

You cannot fix that sleeve.
If you are confident of your run out measurements contact the manufacturer and expect that you will have to send it back for a replacement.
It is not bashing if you are correct. You are merely stating fact.

My smith is a couple of hours away with the reamer. These things always seem to be crop up on the weekend. I'll contact the MFG and get their input.

 

[Iowa Fox]

I'm chasing the same thing, different cal different seating die. My next step is to dig out my K&M long tapper adjustable neck chamfering tool to see if it helps. If I can find it.

 

[farmergreg]

When seating, is the sleeve lifted by the shoulder of the case, or by the shell holder. If the sleeve is lifted by the case shoulder, the male cone of the case is forced to be centered in the female cone in the sleeve - it is held ridgedly and cannot move sideways... but if the sleeve is long enough for it to hit the shell holder, the the case can flop around inside of the sleeve and it has no guidance or support - so it might as well be a simple seating die.

Good idea, but I checked that too. The brass stops entering the sleeve slightly before the extraction groove.

 

[ireload2]

Farmergreg
I forgot to mention an episode I had with a seater die. I bought a Rem 700 25-06 in 1972 and it never shot very well - about 1.250 groups at 100 yards.
One day I rolled a few rounds across a table and the tips of the bullets wobbled up and down what looked like .010 to .012.

Previous to that I had ran an engine lathe 5 years or so and I knew I could easily see .003 run out. I took the seater to work and chucked it in a new Leblond Regal. The run out looked like .030. It was so bad I didn't bother to measure it. It appeared that the drill had wandered way off center when drilling the seater die body.

I called RCBS and they said send both dies back with sample cases and bullets.
About 10 days later I got a new set of dies and my brass and bullets back. All the bullets were seated with very little run out. My loaded ammo showed no visible run out when rolled across the table top. At the range the groups shrank to around 5/8" at 100 yards. That is a strange rifle because 200 yard groups are only about 7/8". I cannot complain about the replacement dies.

 

[farmergreg]

Farmergreg
I forgot to mention an episode I had with a seater die. I bought a Rem 700 25-06 in 1972 and it never shot very well - about 1.250 groups at 100 yards.
One day I rolled a few rounds across a table and the tips of the bullets wobbled up and down what looked like .010 to .012.

Previous to that I had ran an engine lathe 5 years or so and I knew I could easily see .003 run out. I took the seater to work and chucked it in a new Leblond Regal. The run out looked like .030. It was so bad I didn't bother to measure it. It appeared that the drill had wandered way off center when drilling the seater die body.

I called RCBS and they said send both dies back with sample cases and bullets.
About 10 days later I got a new set of dies and my brass and bullets back. All the bullets were seated with very little run out. My loaded ammo showed no visible run out when rolled across the table top. At the range the groups shrank to around 5/8" at 100 yards. That is a strange rifle because 200 yard groups are only about 7/8". I cannot complain about the replacement dies.

After high school I got an associate degree in Tool & Diemaking. But didn't work in the trade very long before greener pastures beckoned. (literally!)

I still dabble with machining and you're spot on being able to see things that aren't running true.

 

[Shynloco]

farmer greg,
If that's Winchester .308 Brass, the problem may be the brass itself. I use Lapua primarily except in my son's Rem 700 .308 that he uses to hunt and plink with. Something I've tried in the past (and as someone above stated) try resizing your brass in the FL Die, throw the lever once and then turn the brass 180 degrees and throw the lever a second time. If that doesn't improve the concentricity, try another thing I've found that works. And that is screw in your Mandrel die and lube the Mandrel. Then throw the lever REPEATEDLY (5-6 times) running the Mandrel up the casing mouth until you feel the tightness in the brass less considerably. That tightness is a crooked neck getting straighten out. Then run the brass through the FL Die again and see what your runout is. I've had good success with that method especially when I do it with once fired LC brass (when I first get the stuff) for my son's AR 10. It's not a 100% thing because some brass is beyond help. That brass should be used either for Foulers or relegated to the round can because junk is junk no matter who makes it.

Alex

 

[farmergreg]

farmer greg,
If that's Winchester .308 Brass, the problem may be the brass itself. I use Lapua primarily except in my son's Rem 700 .308 that he uses to hunt and plink with. Something I've tried in the past (and as someone above stated) try resizing your brass in the FL Die, throw the lever once and then turn the brass 180 degrees and throw the lever a second time. If that doesn't improve the concentricity, try another thing I've found that works. And that is screw in your Mandrel die and lube the Mandrel. Then throw the lever REPEATEDLY (5-6 times) running the Mandrel up the casing mouth until you feel the tightness in the brass less considerably. That tightness is a crooked neck getting straighten out. Then run the brass through the FL Die again and see what your runout is. I've had good success with that method especially when I do it with once fired LC brass (when I first get the stuff) for my son's AR 10. It's not a 100% thing because some brass is beyond help. That brass should be used either for Foulers or relegated to the round can because junk is junk no matter who makes it.

Alex

Hey Alex thanks for the response, great suggestion for salvaging cases.
In my situation my fired cases are .0005 to .0015 TIR on the worst.
After sizing with a collet die the cases are still in that range.
Only when I go to seat I'm I inducing more run-out. At this point I'm still focused on the seater, specifically the support sleeve where the tolerances seem to be off.

 

[blastit37]

farmergreg: In your opening post, did you mean .0005-.0015 instead of .005-.0015?

 

[farmergreg]

farmergreg: In your opening post, did you mean .0005-.0015 instead of .005-.0015?

Crap!! Yes, Good catch, I just corrected it.
Thanks for proofreading for me.

 

[Fotheringill]

Based on my own observations only-

I have also been bothered by runout with .223's- the only reloading I do.

I have found there is a slight average difference in TIR between my RCBS Competition seater being on average worse by .0005-.00075 than Redding Competition seater.

BUT- I also found a difference by an average of .0001 and .00015 between Redding Competition neck bushing die sizer, RCBS vanilla neck sizing die and Lee collett neck sizing die with Lee being the best. Lee has never gone off more than .00025 in TIR after seating and the others never more than .0004. I am just kind of PO'd that the $20 neck sizing die performs better than the much more expensive other sizing dies.

I DO rotate the shell when using Lee and I also rotate the shell when seating.

I would also suggest the OP carefully inspect the shell holder or replace it and the make sure the shell is snug against the closed side of the shell holder before seating.

What I am doing, right or wrong with the Lee neck sizing die is to have a loose top, tighten it just up to point where resistance is encountered and the top is no longer loose and then start to size the necks. When seating, there is a very consistent feel to the pressure needed to seat. In fact, I can just let the ram arm on my Rockchucker drop down on its own. Never a tight fit and never a loose fit, but a very consistent fit.

 

[farmergreg]

Based on my own observations only-

I have also been bothered by runout with .223's- the only reloading I do.

I have found there is a slight average difference in TIR between my RCBS Competition seater being on average worse by .0005-.00075 than Redding Competition seater.

BUT- I also found a difference by an average of .0001 and .00015 between Redding Competition neck bushing die sizer, RCBS vanilla neck sizing die and Lee collett neck sizing die with Lee being the best. Lee has never gone off more than .00025 in TIR after seating and the others never more than .0004. I am just kind of PO'd that the $20 neck sizing die performs better than the much more expensive other sizing dies.

I DO rotate the shell when using Lee and I also rotate the shell when seating.

I would also suggest the OP carefully inspect the shell holder or replace it and the make sure the shell is snug against the closed side of the shell holder before seating.

What I am doing, right or wrong with the Lee neck sizing die is to have a loose top, tighten it just up to point where resistance is encountered and the top is no longer loose and then start to size the necks. When seating, there is a very consistent feel to the pressure needed to seat. In fact, I can just let the ram arm on my Rockchucker drop down on its own. Never a tight fit and never a loose fit, but a very consistent fit.

Thanks for your input. Sounds like you are pretty exacting in your tolerances.
I've found gunk in the shellholder before, these rounds were loaded on the co-ax which has the spring loaded centering shellholder.

Update: manufacturer is sending a new one. Returning the old one for inspection.

 

[farmergreg]

Quick update:
Borrowed a Redding competition seater.
Disassembled and cleaned...thought I'd check the sleeve for runout.
.001 TIR runout on the base end .003 TIR runout seater plug end


TIR measured inside the neck prior to seating, TIR measured just ahead of the bearing surface after seating.

4 cases seated:
.002 before / .0015 after
.001 before / .003 after
.0015 before / .0035 after
.0015 before / .004 after


I'd like to try seating with a CONCENTRIC seater once and see the result.

Is it impossible to mfg this sleeve to maybe .001 runout?

Or am I being too anal?

 

[farmergreg]

Continuing the quest:
Disassembled my Forster 223 seater and checked the chamber / sleeve: .0005 TIR both ends.

Incidentally called Redding and asked the tech what their tolerance was for their competition seater chamber / sleeve regarding runout: "we can't tell you that, its a propriety secret"

 

[Patch700]

Continuing the quest:
Disassembled my Forster 223 seater and checked the chamber / sleeve: .0005 TIR both ends.

Incidentally called Redding and asked the tech what their tolerance was for their competition seater chamber / sleeve regarding runout: "we can't tell you that, its a propriety secret"

LOL!! With trade secrets like that they'll have no worries pumping out the finest paper weights the industry has known lol.

I would have chuckled and asked to speak to someone who is qualified to read instruments please.. lol

 

[farmergreg]

LOL!! With trade secrets like that they'll have no worries pumping out the finest paper weights the industry has known lol.

I would have chuckled and asked to speak to someone who is qualified to read instruments please.. lol

The conversation got quite convoluted.
Redding: "Do you want to send it back for us to evaluate"
Me: "If you can't tell me the tolerance, what would the point be?"
Redding: "If we determine it's out of specification, we will replace it"
Me: "It's not my die nor do I intend to send it off for an evaluation when I have no idea what you're evaluating for. IE tolerance"
Redding: "that's the best we can do"
Me: "Good bye"