Non scientific test of several 308 seating dies

[farmergreg]

building on this thread:
http://forum.accurateshooter.com/threads/308-concentricity-issue-possibly-seating-die.3921892/

Original dies in that thread were Whidden. Sent the dies back, his diagnosis was bad brass. Not going to argue as winchester brass doesn't have a stellar rep. While waiting for the return of the Whidden dies, I ordered some Lapua 308 palma brass and borrowed a couple of seaters.

Non scientific: IE 10 random cases were prepped and seated with each seater die.
Brass was expanded and chamfered prior to seating. The case runout was .001 to .0025 inside of case neck prior to seating.

Sierra 2156 projo.
Forster Co-AX press

Going from best result to the worst:
Forster Ultra 308: .0026 TIR
Redding Competition: .0027 TIR
Whidden: .00315 TIR
LEE: .00335 (Thought I'd throw that one in as it came with my collet die)

Lets talk precision of the floating cartridge support sleeve (TIR measured at base and neck)
Best to worst:
Forster: .0015 Neck .001 Base
Redding: .003 Neck .001 Base
Whidden .007 Neck .0065 Base
(Whidden runout was consistent, low side was equal, basically the hole was straight though not concentric with the OD)

Observations:
Whidden: Said the runout didn't matter as long as the hole was straight.
Redding: Couldn't or wouldn't tell me what their tolerance is. (suggested I return the die for inspection / replacement at their discretion)
Forster: replaced a sleeve in my 223 die that was out .005 at the neck. (so that's too loose of tolerance for them)

My conclusions:
I'm going to buy Forster.
Lapua Brass isn't that straight.
.0001 TIR= 3.8% The LEE is 27% worse than the Forster.

 

[Randy L]

Thanks for taking the time to post the results, farmergreg. I've had good results with Forster products as well.
Randy

 

[NorCalMikie]

Forster Precision Bushing Bump Dies and RCBS Compitition Seater die! Combo can't be beat.
Why check the runout if they're all going in the same hole?

 

[Canadian bushman]

Would you be willing to swap cases and dies and do the experiment after firing?

I would be interested to see those results.

 

[Gman]

I would like to see the results from a Wilson seating die.

 

[farmergreg]

I would like to see the results from a Wilson seating die.

I'm game!
I could mail you 10 random pieces and projos and you could report back?

 

[Steffen Bunde]

Greg, Have you tried just barely seating the bullet then rotating the case 180 degrees and finish seating? From Mid Tompkins

 

[HTSmith]

I'm curious as to how they shot.

 

[farmergreg]

Greg, Have you tried just barely seating the bullet then rotating the case 180 degrees and finish seating? From Mid Tompkins

In my other thread I tried seating them 1/3 of the way in and rotated as I seated.
For this "test" I shoved 'em in!

 

[farmergreg]

I'm curious as to how they shot.

Probably shoot fine....in competent hands!

60º and calm this weekend, perfect for load tests....but I'm resurrecting the yard and flower beds from the winter ugly...(Per the Mrs. direction!)

 

[J. Gunz]

I think Bryan litz did a test awhile back that showed seating half way then rotating and seating the rest increased concentricity by a large margin. I'll have to check some books to confirm if it was him.

 

[ireload2]

Thanks for reporting the data and facts.
Many times a premium item will have a premium reputation based on warm fuzzies and few objective tests.

 

[farmergreg]

Greg, Have you tried just barely seating the bullet then rotating the case 180 degrees and finish seating? From Mid Tompkins

Update:
10 more random Lapua seated using the 180 degree turn method with the Forster die:
.00213 TIR (this is a .0005 improvement or 19%) impressive!

 

[savagedasher]

Update:
10 more random Lapua seated using the 180 degree turn method with the Forster die:
.00213 TIR (this is a .0005 improvement or 19%) impressive!

I have to wonder was it the seating or the brass preparing that made the change?
Larry

 

[farmergreg]

I have to wonder was it the seating or the brass preparing that made the change?
Larry

I prepped 100 cases, expanded and chamfered them. Just grabbed 10 out of that lot, they were prepped the same as the others.

To move this toward SCIENTIFIC I'd have to measure each new case for runout. But that doesn't necessarily correlate to bullet runout either.

 

[savagedasher]

I prepped 100 cases, expanded and chamfered them. Just grabbed 10 out of that lot, they were prepped the same as the others.

To move this toward SCIENTIFIC I'd have to measure each new case for runout. But that doesn't necessarily correlate to bullet runout either.

The. .0005 it more of the question just the heat from your finger wold show that little of change . Larry

 

[Joe R]

building on this thread:
http://forum.accurateshooter.com/threads/308-concentricity-issue-possibly-seating-die.3921892/

Original dies in that thread were Whidden. Sent the dies back, his diagnosis was bad brass. Not going to argue as winchester brass doesn't have a stellar rep. While waiting for the return of the Whidden dies, I ordered some Lapua 308 palma brass and borrowed a couple of seaters.

Non scientific: IE 10 random cases were prepped and seated with each seater die.
Brass was expanded and chamfered prior to seating. The case runout was .001 to .0025 inside of case neck prior to seating.

Sierra 2156 projo.
Forster Co-AX press

Going from best result to the worst:
Forster Ultra 308: .0026 TIR
Redding Competition: .0027 TIR
Whidden: .00315 TIR
LEE: .00335 (Thought I'd throw that one in as it came with my collet die)

Lets talk precision of the floating cartridge support sleeve (TIR measured at base and neck)
Best to worst:
Forster: .0015 Neck .001 Base
Redding: .003 Neck .001 Base
Whidden .007 Neck .0065 Base
(Whidden runout was consistent, low side was equal, basically the hole was straight though not concentric with the OD)

Observations:
Whidden: Said the runout didn't matter as long as the hole was straight.
Redding: Couldn't or wouldn't tell me what their tolerance is. (suggested I return the die for inspection / replacement at their discretion)
Forster: replaced a sleeve in my 223 die that was out .005 at the neck. (so that's too loose of tolerance for them)

My conclusions:
I'm going to buy Forster.
Lapua Brass isn't that straight.
.0001 TIR= 3.8% The LEE is 27% worse than the Forster.

View attachment 1005905

Take it from someone that used to drive himself crazy about concentricity, you're wasting your time.

I worried about it until I had this experience with a new rifle http://forum.accurateshooter.com/threads/my-new-260-ai-build.3909184/ . 30K runout and one hole results.

Now, I just setup the dies straight and hardly even use my $400 CTK runout gage anymore. There are a lot more important things that have more impact then runout.

Good luck,

Joe

 

[Puzzaz01]

Greg, Have you tried just barely seating the bullet then rotating the case 180 degrees and finish seating? From Mid Tompkins

This is true.

 

[farmergreg]

Take it from someone that used to drive himself crazy about concentricity, you're wasting your time.

I worried about it until I had this experience with a new rifle http://forum.accurateshooter.com/threads/my-new-260-ai-build.3909184/ . 30K runout and one hole results.

Now, I just setup the dies straight and hardly even use my $400 CTK runout gage anymore. There are a lot more important things that have more impact then runout.

Good luck,

Joe

Amen!
But IF you're doing a job why not strive for the best result?

 

[Scott Harris]

Greg, I think your runout has far more to do with the press & die setup than the dies themselves. I bet I could take any of the dies that you have there and reduce the seated bullet runout to near zero. The fact that all the dies have similar runout confirms, in my mind at least, that you do not have a die problem. Also, the differences in runout between the dies is not statistically signficant, based on the sample size shown in your picture. Translation, they all seem to work about the same.

Also, keep in mind it's a cumulative process. So, brass with .0025 runout is going to show up as seated bullets with similar or greater runout. Personally, I find the better commercial seaters to all be capable of seating bullets perfectly. I did a test years back with hundreds each seated on a Forster, Redding, Wilson inline. There was no difference in their ability to seat bullets well.

Sizing dies are where I find big differences in the end result. If you want to learn more, measure the runout on your fired brass, then on sized cases, then on seated bullets. If you see things improving at each step, then you have a good setup. Major areas to focus on are quality of the sizing die, your die/press setup.....that's the big one for the seaters. Now, a Wilson works well by default because it is a press-free setup. But that does not mean you can't get a Redding or Forster to work just as well.....float the die.

Are you testing on new brass? New brass is not going to be very straight, but it will be after 2 firings, assuming your chamber is straight. Best to test your seater when starting with brass that has minimal runout.