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Challenge to you gurus! Set up new Forster Ultra seater. Data/numbers here. WTHeck...

Wanted to reduce runout after getting 21st century gauge last week. It's an incredible tool by the way, even I can use it. Bought this Forster ultra seater die for 223. Using 77 SMK moly bullets in freshly trimmed to within a thou Lapua brass that's been fired 3/4 times. Champher/deburr cleaned primer pockets, tumbled, etc.

Had trouble from start setting forster seating die up. Instructions said after compressing bushing to back out at least one turn. I did that and followed directions to adjust from there with seating stem on top, where flat screw driver fits. I turned it out several turns. Then set first bullet almost all the way in case, tip barely protruding. Did similar versions of that 2-3 x, the started over and after compressing bushing, I backed out about 5 turns, rather than the 'at least one' as directions said.

That got me close, and I adjusted the top seating stem, then locked it all down. I loaded 2-3 rounds at 2.256-2.257 and called it good. Main objective was to compare runout to same brass, same load, with my redding seater I had been using. The results of this Forster were worse overall, with more extremely off examples than my standard seater.

What's more puzzling is that I essentially loaded two groups. I loaded 28 rounds and using ogive/base measurements with hornady bullet comparator, they were extremely uniform, but two groups, separated by 7 thou. I'm lost. I locked die down first. I changed nothing. The results were as random as they could be. Meaning, the rounds didn't get longer at one point. Didn't have a pattern or shifting.

Literally imagine pulling 13 random rounds out of my loading block and them all being within +/- a thou in ogive/base. Then the remaining 15 rounds were the same, +/- a thou, but 7 thou longer than the other group. Numbers are below. I'm praying it means something to someone here.

I'm assuming I set seater up improperly, but have no clue about the randomness of two otherwise very consistent COAL groups. And in similar proportion, 13 in one group and 15 in the other. And the runout was terrible in both groups. Worse than my standard redding seater. How did I screw things up this bad?


13 round 'group'

On Hornady bullet comparator ogive/base measurement ...

All were between 1.880-1.882" (1.881 avg)

COAL with calipers ...
2.266
2.267
2.266
2.267
2.267
2.265
2.269
2.265
2.270
2.265
2.264
2.272
2.260




Second 'group' of 15 rounds ...

Hornady comparator base/ogive 1.873-1.875"

COAL with calipers...

2.258
2.253
2.258
2.262
2.259
2.260
2.256
2.258
2.256
2.257
2.264
2.260
2.263
2.260
2.259



Now the really painful part, runout... On 21st century gauge...

The 1.874 avg group had the following variation in thou...

3
8.5
7.5
9.5
5
4
6
5.5
2.5
2.5
4
1.5
6
3.5
6



The 1.881 avg group was...

2.5
3
4
4
2
6
4.5
6
2
6.5
5.5
1
5.5





Dan
 
Try this , raise arm of press to top of stroke , screw seater die down until the sliding chamber is fully retracted into the body of the die... lock the die down there.

Remember , it's the sliding chamber that gives you the support as if it were in a chamber while the bullet gets seated so you want to utilize that aspect of the die.

I have even gone as far as to setup the die so it has a small amount of cam over and then lock it down.

Good luck.
 
The instructions are correct. Run the die down then back out one turn, then on the micrometer top adjust it out 4-5 revolutions and then back off the seater steam. If you know what you want your OAL to be seat a bullet measure. Then you can do one of two things, measure how far out the seater stem is on top of the die with your calipers and adjust it down or out the desired amount to get your OAL you want. Or just adjust the micrometer top to your desired length.
I myself like to keep the top set on a zero Mark and adjust the stem, then use the top to fine tune my seating depths.
 
That's what I was attempting, keeping micrometer on zero. I had to back seater die out about 5 full revolutions to prevent grossly over seating bullets. From there I could adjust with stem to get where I wanted, or within range. But by backing seater die up so much I can't see the bushing, and I'm not sure how much it's being used.


Thanks for set up insights. Most helpful.


How in the heck am I getting two rather uniform +/- a thou COAL that are fairly equal in number and 7 thou apart?

Why is my runout worse than with my standard seater? Hope I'm just not using the Forster seater properly. Everything I read suggested this was a great way to reduce runout. But my numbers are all over the place.



Dan
 
Patch700 said:
Try this , raise arm of press to top of stroke , screw seater die down until the sliding chamber is fully retracted into the body of the die... lock the die down

That was the first thing I did Patch. But I backed the die out one turn after doing so per directions, then locked it down. Seated a bullet and the tip barely protruded out of the case mouth. Then I worked out till I had the die about 5 full turns out, thats what it took the stop grossly overseating bullets down into the mouth of the case.

While I obvioulsy don't fully understand this die yet, I don't feel like I'm using the sliding bushing much by having die backed off shell holder five turns. Just seems like I would feel bullet going into sliding bushing more before proper seating depth was achieved. To me, it feels like a very short seating. Make me wonder if I'm using the bushing, the sliding up and down aspect of it, at all. It's so far up I can't see anything, due to the five turns the die was turned up.



Dan



Still, how am I getting two lengths of loaded rounds, 7 thou apart, but uniform within the two respective groups. Literally, how is that possible.
 
SG4247 said:
Runout:

How much runout did the brass have on the neck, prior to seating the bullet?


I don't know exactly, didn't record the numbers. I was mainly trying to see if this Forster Ultra die would decrease the runout I saw the other day. Looks like I've opened a can of worms. I don't turn necks but use Lapua brass that is prepped quite well otherwise.

Playing with some brass on my 21st century gauge, I was seeing 2-3 thou a good bit, some a bit better, some worse. But didn't write down any numbers. I was just getting an idea of how much runout I was introducing in the sizing stage. Fire formed runout was quite minimal, as I had read here that it would be.

That casual observation along with my loaded round runout testing suggested the majority of my runout was being picked up in the seating stage. That's why I bought the Forster first. Thought about buying the Harrel? Sizer die. But geesh, after this I am starting to question the whole shebang.
 
A seating die will not straighten crooked brass. If you're seeing .003" runout on sized brass, that is where your problem originated. Not surprising to see double the runout on loaded rounds especially the farther towards the bullet tip that you run the indicator. As far as setting up the die, you can turn the micrometer section up on the die past the -0- mark and turn the seater stem section out the top of the micrometer piece a long way too so that way you can screw the die farther into the press without over seating.

As for the seating variation, make sure the bullets are not bottoming out in the stem, which I doubt those bullets are. The next thing I would blame it on is variance in the actual bullet between the datum you're measuring to and the datum your seating stem is contacting. Of course there is always the chance that the die is messed up some way but I have had quite a few in different calibers and personally never had a problem. Hope you get it figured out.
 
I'm confused. You bought a 21st Century arbor press last week (I'm guessing the hydro press) but are using a Forster Ultra micrometer seater ? What press are you using for the Forster seater ?
 
I set mine up like James does. First, I clean the die. Second, I raise the ram with a case, screw the die down to coil bind, then back it off, but only enough to position the micrometer marks so I can read them. A 1/4 turn is plenty. At this time I also check that the shell holder does not contact the chamber sleve. If it does, I shorten the sleve. I want the case shoulder to push the sleve up, not the shell holder. I feel this centers the case better. Third, I adjust the micrometer to zero, and turn the seating stem all the way up. Fourth, I insert a case and bullet and raise the ram, then turn the stem down until you feel it touch the bullet firmly. Then lower the ram, screw the stem down about 3 turns and seat the bullet. At this point, do as James suggests, measure the length of the round, determine how much shorter you want it, and use a caliper to lower the stem by that amount. Then use the micrometer to fine tune.

As far as your variance in depths, I too suspect your tools have different datum diameters.
 
I use the Hornady bullet comparator on my caliper. No anvil base, just spin the case head on the caliper arm to settle the reading. Very consistent results. All 28 rounds checked at same time. Same technique.

Also notice the COAL is generally shorter on the short ogive/base group, which is 7 thou shorter than the longer group. The longer groups, also had ogive/base very tight at +/- thou. Looking at COAL of the 7 thou longer group, they are generally longer than the short group.

To me, and I'm dense with these matters for now, that makes it impossible to claim that variances in datum measuring, etc are the issue with me having two distinctive groups length wise. Precisely 7 thou apart. The COAL is different as well for the long group, and the short group.

With all that data, it seems the only possible explaination is that the bullets are being seated to TWO depths in this die. I have literally made two groups, 13 in one and 15 in the other, that had +/- thou ogive/base variation, yet were 7 thou apart.

???

Thanks for any help. I'm at a loss honestly.




Posting numbers again, so anyone looking won't have to go all the way back up top...





13 round 'group'

On Hornady bullet comparator ogive/base measurement ...

All were between 1.880-1.882" (1.881 avg)

COAL with calipers ...
2.266
2.267
2.266
2.267
2.267
2.265
2.269
2.265
2.270
2.265
2.264
2.272
2.260




Second 'group' of 15 rounds ...

Hornady comparator base/ogive 1.873-1.875"

COAL with calipers...

2.258
2.253
2.258
2.262
2.259
2.260
2.256
2.258
2.256
2.257
2.264
2.260
2.263
2.260
2.259



Now the really painful part, runout... On 21st century gauge...

The 1.874 avg group had the following variation in thou...

3
8.5
7.5
9.5
5
4
6
5.5
2.5
2.5
4
1.5
6
3.5
6



The 1.881 avg group was...

2.5
3
4
4
2
6
4.5
6
2
6.5
5.5
1
5.5





Dan
 
Do you FL size with a captured (sleeved) Die like the Redding or Forester comp dies? Also, Boyd has explained a bit on how to get the most out of Forster dies. Try the search option.. I'm thinking of a Arbor press this season with a force measurement option..


Ray
 
I use redding deluxe FL sizer die. Just put the carbide sizer button in it recently.

I will search more regarding old threads. I've read hundreds. Lots of great info from Boyd Allen for sure.

Inconsistent I get, I don't like it, a preoccupation is being created with getting rid of it. I feel like the people that turn light off, then on to prove it was off, then off again. I'm one step away from counting Oreos in the bag at Walmart to buy the bag with the most. Screwed up. Surely. Dang 21st Century gauge. I was fine till I saw how bad my ammo is. Hah.


What I can't wrap my head around is TWO groups lengthwise that are precisely 7 thou apart.

I am also surprised the runout is so much worse with the new Forster seater, compared to my, by all accounts, lackluster standard seater. Turning necks and other work needed to get runout out low, sure I get that. But the fact that it's worse is surprising. Some nearing double digits. Factory seater was averaging 4 thou or so, only two of about 30 were 6-7 thou, my previous worst runout.
 
Danattherock said:
I use redding deluxe FL sizer die. Just put the carbide sizer button in it recently.

Bushing die, do away with the sizer button.. That could be a couple .001 right there. If your measuring run out, you may want to turn your necks enough to clean them up.


Ray
 
Thanks Ray. I plan on looking into the 21st century mini lathe to turn necks. If I can get past this issue. Hard to spend another $300 when I'm making banana rounds.

;D
 
Dan,
I re-read your post to make sure I understood it. If after your initial trial and error, you have the WHOLE DIE backed out 5 turns, then you don't have the die set up correctly and the sliding bushing is providing no support to the case at the bottom of the seating stoke. Go back to square 1 and reset the die to ONE TURN OUT. It sometimes helps, before locking it down, to put a flat washer between the die and the shell holder to take the lash out of the die body threads, then set your lock ring. Then use the adjustment on the seater stem to give you the longer initial seating depth you are looking for. The screw that forms the seater stem is longer than you think it is, and it has finer threads than the die body, so you have to turn it alot to gain length.

Elkbane
 
I just skimmed this thread, and it looks like the guys are pointing you in the right direction. Have you outside neck turned to a uniform wall thickness? I have had this give me inconsistencies in OAL before.
 
Good observation Lawrence. There's another post from a few days ago about seating depth that deals with that, re' the shape of the nose of the bullet and effects on seating depth. I see this all the time when I measure bullets (lump into definitive size groups) - not even different production runs - there is in-line and across line variation in every mass production process. It helps to find a manufacture who understand this and has a quality control approach which address it. And hopefully their bullet will shoot in your barrel......

I guess what I'm thinking is that the seating depth issue and the runout issue related. If the sliding insert in the die is not in the correct position, the case "floats" inside the die, i.e. it can get sideways during the seating stroke. That's why the insert is there, to keep the case straight so that the bullet can go in straight.
My suggestion is to fix that first, and then see if that helps the runout. If the runout gets fixed, I'm guessing that some of the seating depth issues get fixed.

If, as I suspect, the case is floating around inside the die, and seating is happening on an unsupported case, the bullet can go in crooked, right? Which results in increased seating force and the bullet tip being offset from centerlne of the case (the seater stem contacts the bullet nose at a different place than on a straight bullet), each of which which could create a seating depth different from that of a supported case with concentrically seated bullet.......
Elkbane
 
So, instead of trying to solve two problems simultanesly, just focus on one.

When you get to the runout problem - go back and read this post again slowly:

http://forum.accurateshooter.com/index.php?topic=3863973.msg36515606#msg36515606

Glenn
 

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