Forster mic seater acceptable run out?

longgunJR

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Apr 8, 2019
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Hi all,
What do you guys consider acceptable as far as bullet run out goes?

I'm loading 6.5x47L with 140 Hybrids using a Forster Ultra micrometer seater and getting up to 0.005" measured at multiple points with a Sinclair concentricity gage. I rarely get less than 0.002" and I've tried both new and 1x sized brass that's trimmed, chamfered, deburred and ran through an expanding mandrel to correct the case mouth bends and burrs.

On my 6.5 Creedmoor using a Redding micrometer seater I can consistently get tir under 0.0025" with Hornady 140 ELD M without any effort at all the only difference being the die.

Both guns shoot tight groups with SDs under 5fps, so the run out isn't necessarily causing any issues but I'm a machinist and having so much run out just bothers me and gives me the impression something is not right.
Forster sent me a new seating stem but didn't make a difference I'm about to send the Forster back and just get another Redding.

What do you guys think?


Cheers...
 
You need to start from the beginning to verify were the run out is being induced from.
New unfired measurement, measured after firing, measured after sizing, measured after seating.
That way your not busy chasing your tail and can pinpoint your next move.
My Forster 6.5x47 seater averages around .001" with three different bullets of varying profiles. (123CC, 130VLD, 130 Hybrids)
 
I’d question the brass and sizing dies far before the bullet seating die.

I use Forster seaters in 223, 260, 7SAUM and 338 Norma and 2 thou is about as bad as it gets but it’s my sizing dies that really get cases straight, the quality seater is just the finishing touch.
 
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Hi all,
What do you guys consider acceptable as far as bullet run out goes?

I'm loading 6.5x47L with 140 Hybrids using a Forster Ultra micrometer seater and getting up to 0.005" measured at multiple points with a Sinclair concentricity gage. I rarely get less than 0.002" and I've tried both new and 1x sized brass that's trimmed, chamfered, deburred and ran through an expanding mandrel to correct the case mouth bends and burrs.

On my 6.5 Creedmoor using a Redding micrometer seater I can consistently get tir under 0.0025" with Hornady 140 ELD M without any effort at all the only difference being the die.

Both guns shoot tight groups with SDs under 5fps, so the run out isn't necessarily causing any issues but I'm a machinist and having so much run out just bothers me and gives me the impression something is not right.
Forster sent me a new seating stem but didn't make a difference I'm about to send the Forster back and just get another Redding.

What do you guys think?


Cheers...

I have the same seater and had a similar problem some time ago.

It seems to me, based on what you're doing above, that there would be two things I'd look closely at. First, I'd look closely at the seating stem by removing it and seeing how well that 140 Hygrid fits. I look to see how snugly they fit where there's little if any wiggling going on. The more wiggle observed, the more runout tends to be induced.

Second, (and one of the things the helped my reduce runout) was making sure the chamfered area in the mouth was uniform all around the rim so that the chamfering doesn't influence how the bullet is entering the neck. Early on I noticed my chamfering was not the same on one side as the other of my case mouths and worked to make it uniform. I change the tool for chamfering to that I could get a chamfer that was really square to the neck and I also found that having a neck with uniform thickness helped with this chamfering as well as with concentricity.

Now I get runouts, using MY Sinclair concentricity gauge, of .002 or better with quite a few better than .001. But occationally, one will run .004 and haven't figure yet why that happens.

And BTW, I use a Forster Co-Ax press. I've seen information showing that even the type of press can make some difference, though the sizing dies and how they're used are the biggest influence.
 
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What type of die are you using to resize the case and neck? Does it use a bushing?
For the 6.5x47L Im using a LE Wilson FL bushing die and a Redding type S for the creedmoor.
However the run out issue exists with new unsized brass that I run through a mandrel before chamfering with a Giraud power trimmer.
I've checked tun out of case mouth and all I get is whatever the wall thickness may vary so 0.001 to 0.002, nothing to rise a red flag. I've also checked tir on 1x fired sized, trimmed and chamfered brass and I don't believe the sizing process is causing a problem.

The press I use is a MEC marksman and it has a floating shell holder feature that self centers to the die.
 
For the 6.5x47L Im using a LE Wilson FL bushing die and a Redding type S for the creedmoor.
However the run out issue exists with new unsized brass that I run through a mandrel before chamfering with a Giraud power trimmer.
I've checked tun out of case mouth and all I get is whatever the wall thickness may vary so 0.001 to 0.002, nothing to rise a red flag. I've also checked tir on 1x fired sized, trimmed and chamfered brass and I don't believe the sizing process is causing a problem.

The press I use is a MEC marksman and it has a floating shell holder feature that self centers to the die.

. . . all very good equipment and wouldn't think any of it has any significant contribution to the runout issue. I happen to use a Giraud trimmer too, which was what really helped give me with getting the uniform chamfering I was looking for (not to mention the speed ;) ).

I'm left with thinking it's something to do with the seating stem. I know there can be variations with anybody's seating stems and maybe you just got one that is a little off ??? Maybe if you call Forster they'll work with you on it?
 
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This can be a long dark rabbit hole. I suggest you use the concentricity gauge to mark your brass. Either that or sell it to somebody you don't like. First of all, there are many variables, and then there is the whole argument does it really even matter.

I used to obsess over it but have not checked it in 2 years. I've got several rifles that will shoot one hole groups when checking zero. I would be willing to bet none of them use ammo with better bullet concentricity than what you've listed.

I've been there, I get it, and I would not waste my time if I were you. Focus on your fundamentals and just enjoy shooting is my advice.
 
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Closing thread for Future reference.

I ordered a Redding Competition seater die just to see if it would make a difference, loaded 100 rounds this weekend and got consistent +/-0.001 TIR and -/+0.001 BTO seating depth all issues went away.
The biggest difference seems to be the geometry of the seating stem and the amount play between spring loaded sleeve and die body, this is tight and very little to no play on the Redding, this being somewhere between 0.005 to 0.01 radial play on the Forster.
Will this make a difference on group size and SDs? who knows but I do have more confidence on the quality of my ammo.

The fit and finish of the Forster die is top notch and they were willing to stand by their product and make it right, they asked me to send the die back along with 4 cases and bullets for an expected turn around of about 3 weeks. I didn't want to wait so I just bought another die as I'm working with a new barrel and tinkering with my loads.

Cheers...
 
for what its worth...ive never had good luck with Forster dies. Hornady has given me better consistency but Redding FL bushing and micro seater dies have been best for me across multiple calibers.

I know Forster gets praised for their dies...but I just dont get the same results others do with them. Always problems with seating depth, runnout and seater. The resizer was also noticeably harder to press vs the other brands.

Just my experience.
 
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for what its worth...ive never had good luck with Forster dies. Hornady has given me better consistency but Redding FL bushing and micro seater dies have been best for me across multiple calibers.

I know Forster gets praised for their dies...but I just dont get the same results others do with them. Always problems with seating depth, runnout and seater. The resizer was also noticeably harder to press vs the other brands.

Just my experience.
I agree that the seater dies are not as good as Redding. I use Redding Competition sesters for all the calibers i reload. But i have gone to Forster FL sizing dies honed to the neck size my brass is turned to. I don’t use a sizing button. They beat whidden bushing dies with whidden bushings. That had been my previous gold standard.

David
 
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