Custom Dies ??? Is it the case ?

[rick smith]

Bluejay, did you remove the expander ball assembly and try sizing without it? Three thousants run out for a hunting rifle is quite acceptable.Rick.

 

[Bluejay]

Bluejay, did you remove the expander ball assembly and try sizing without it? Three thousants run out for a hunting rifle is quite acceptable.Rick.

No, I did not try to resize without the expander ball assembly in place.....I will.

Actually, I removed the expander rod assembly, cleaned it, worked the expander ball with some sand paper and reassembled everything without the decapping pin.
I figured the expander ball would be straighter because it could go all the way back and rest flat against the rod.

Anyway, I am more and more convinced that the big error lies in the seating Die. Tried some other tests and results were awful....

I get 3/1000 runout on resizing, but then it goes "down the drain" when I insert the bullet.... :x

I am thinking of buying a Forster Bench rest seating Die at this point.....

 

[DrMike]

I certainly like my Forster dies. If possible, they are what I use exclusively on my own cartridges.

 

[rick smith]

Another thought comes to mind reference your seating stem. Your bullet tip may be contacting the seating stem before the cup part of the seater contacts the bullet. Ran into that with Berger VLD bullets a few years ago. Redding now makes a seating stem just for the more pointed bullets.
Remove the seating stem and hand insert the bullet, you want full bullet contact and not tip contact. Just tip contact will give you bad run out.Rick.

 

[Bluejay]

Bluejay, did you remove the expander ball assembly and try sizing without it? Three thousants run out for a hunting rifle is quite acceptable.Rick.

I have run some tests without the expander ball assembly in place.

Results are not improving.

I am thinking more and more of buying the Forster Bonanza set.

Another thought comes to mind reference your seating stem. Your bullet tip may be contacting the seating stem before the cup part of the seater contacts the bullet. Ran into that with Berger VLD bullets a few years ago. Redding now makes a seating stem just for the more pointed bullets.
Remove the seating stem and hand insert the bullet, you want full bullet contact and not tip contact. Just tip contact will give you bad run out.Rick..

Thanks for the input Rick.

I do not think so, though. The bullets I am testing (130 grs. AccuBond) are not blunt, but still quite "fat tipped" if compared to Bergers and alike.
The curve on the bullet tip is quite a "regular round" one.

One thing I have noteced is the shell holder does not line up "square" with the bottom of the Die...
Is this important in avoiding runout and, if so, are there ways to eliminate this angle ?

Thanks

BJ

 

[rick smith]

Depends on where it is not level, how much and the cause. Might be able to remove a little from the top/bottom of the shell holder. Misalingment of the press to the die will cause run out. That would be the FL die since the seating die probably doesn't touch the shell holder. Since you have run out down to 0.003" with the FL die, now concentrate on the seater. Make sure the case mouth has a good chamfer. Did you try setting the seater stem as I stated?Rick.

 

[Guest]

I'm with Rick on this one - I think the issue is in the seating stem. I've heard from several folks that the AccuBond's tip contacts their seating stem. I'd check that for sure before investing any more money in dies of a different brand/type. If there's no tip contact, then the new dies can be ordered straight away.

Overall, your loading leaves little to be desired, based on your results. Good luck running down this last demon. Unfortunately, I always find another, smaller, more obscure demon after the one I'm chasing has been eliminated!

 

[Bluejay]

......Since you have run out down to 0.003" with the FL die, now concentrate on the seater. Make sure the case mouth has a good chamfer.

I am using a friend's resizing Die now, which seems to perform slightly better than mine. I run a test on 10 cases, measuring prior and after resizing.
5 cases came out with a runout of 2/100th, and the other 5 were running from 3 to 4/100th of millimeter.
Full resizing, down to the shell holder touching the bottom of the Die.

As far as chamfering, yes, I do on all of my cases.

......Did you try setting the seater stem as I stated?Rick.

......I'm with Rick on this one - I think the issue is in the seating stem. I've heard from several folks that the AccuBond's tip contacts their seating stem. I'd check that for sure before investing any more money in dies of a different brand/type. If there's no tip contact, then the new dies can be ordered straight away.

I have checked the seating stem. Pulled it out and measured.....
Between the tip of the bullet (.264" AB 130) and the end of the hole there is still over 1,5 millimeter (0,38") clearance, so I'd assume this is not the source of the problem.

 

[Guest]

Not sure what you have access to, but it certainly sounds like you're very detail oriented, and could measure the impact easily, but perhaps try a different seating die - like a Hornady or Forster, which will have a movable "sleeve" that centers the bullet in the case mouth. This might be the trick for controlling that last little bit of runout resulting from your seating die.

Good luck. Oh, and at least suffering this runout issue is only causing you to shoot very good groups, as opposed to great groups!

 

[rick smith]

Just hit the wrong button and erased my message. Will just hit the high points; the seating die should not make contact with the shell holder, crimping groove in the die should not contact the case, set the seating stem with a loaded case that has the least run out even if you have to force the loaded round into zero run out--drill a hole in a board that wil just acept the case neck of a loaded round(dummy round), with a little pressure on the case neck you will be able "bend" the round into zero run out. Have you measured case neck thickness for uniformity?
Even if you have to buy another seating die, you will have learned from this exercise. Sometimes we chase our tails trying to solve loading problems.Rick.

 

[Bluejay]

... perhaps try a different seating die - like a Hornady or Forster, which will have a movable "sleeve" that centers the bullet in the case mouth....

That's exactly what I am going to do ! :mrgreen:

I am going to order a Forster Bench rest seating Die next week.

Finger crossed !
:wink:

 

[Bluejay]

...the seating die should not make contact with the shell holder, crimping groove in the die should not contact the case

Rick, perhaps you have misread. I was talking about the resizing Die, not the seater :mrgreen:
Seating Die does NOT contact the shell holder, nor the crimper touches the case...

....set the seating stem with a loaded case that has the least run out even if you have to force the loaded round into zero run out--drill a hole in a board that wil just acept the case neck of a loaded round(dummy round), with a little pressure on the case neck you will be able "bend" the round into zero run out.

Maybe I will give it a try, even though I almost set my mind on the Forster "solution"... :mrgreen:

Have you measured case neck thickness for uniformity?

Nope. This is something I have never done.

Even if you have to buy another seating die, you will have learned from this exercise......

That's for sure Man. And thanks to people like Yourself and Others on this forum, who spare their time trying to solve other People's (little) problems....
:wink:

 

[rick smith]

Just keep us up to date on what you do.Rick.

 

[Bluejay]

Ok, here we go.....

I've got the Forster BR Seating Die and used it for two loads.
Same powder type and load, different bullets.
Load # 1 was with Nosler 130 grs. AccuBond, while load # 2 was behind Lapua 139 grs. Scenar bullet.

Average runout of all loaded rounds run from 4 to 5/100 of a millimeter, which I think is quite good.

After zeroing my rifle with load # 1 (2" high @ 100 meters) I started with the 5 shot group, which I am posting a photo here below :

Range : 176 meters (190 yds. approx.) - 5 Shots AccuBond 130

Then, I proceeded to test a 7 shot group with the Lapua - load # 2 (without zeroing)
Here it is :

Range : 176 meters (190 yds. approx.) - 7 Shots Lapua Scenar 139

I'd say the AccuBond is better at this distance.

Why is it that Lapua are impacting so high than AccuBond (+ 3 cm.).
Powder load is the same and bullet weight is similar (130 vs. 139).
Could it be the different shape, which makes the Lapua to have less contact with the rifling, because of the shorter "cylindrical portion" - hence less friction) ?

What do you think ?

:mrgreen:

 

[Guest]

That kind of point of impact difference is very likely due to barrel harmonics, I suspect. The two different bullets, which have different shapes and bearing surfaces, as you've observed, will "move" differently down the barrel, creating harmonic vibration in the barrel. Depending on where the barrel is in the oscillation of the basically sine-wave type vibration, you'll get slightly different points of impact.

On the other hand, it appears you have found the issue with your prior groups not being what you want from the rifle.

 

[DrMike]

POI often deviates based on barrel harmonics, just as dubyam explained. The difference in bearing surface, bullet shape, weight distribution all are involved in determining barrel time for the bullet and how the barrel reacts. It does look as if you are well on your way to where you want to be. I do like the Forster BR dies. Whenever possible, these are the dies I use for my personal rifles.