Query: Brass concentricity?

[Thor357]

Let us all know how the results turn out. I'm interested in just what you did and what the results are.

My advise, huh? uh-oh!

200 rounds is sure a lot for load development testing. Just a thought as you head out tomorrow . . . if your shoot dots along a horizontal like as I suggested, if the first 3 shots on a dot are greater than 1 moa apart, STOP, there's no point in shooting more of that load to try and improve because it's already shown you it's not a load that's going to work (assuming you're looking for something under 1 moa).

I will let you know, for sure.
I made a total of 200 rds but only 50 are made using your advice. The rest are testing other things but still using the same powder/bullet combo (trying to use up this powder!).
I downloaded some targets similar to the ones you have. So well see what I end up with.
Oh, and yes, my goal as always is sub-MOA. I usually achieve that but not as often as I'd like.
Oh yeah, almost forgot, I bought 200 of the Sierra Match Kings in 169gr (#2269). I made some dummy rounds using Lapua brass that has been shot maybe 5-6 times. They all came out 0.000-0.0015!!!
I don't have enough Lapua brass to do any real testing with. I've mostly been using Starline brass but it's all tied up in today's testing so I'll have it for these 169's after today.
Thanks again for your help/advice, I'm eager to see if I'm an apt pupil (probably not!!!)

 

[Thor357]

there's no identifying where the measured run-out is really at.

Actually there is. The instruction sheet that comes with the gage says to find the lowest result and then use the screw fixture to "push" on the bullet to just past the highest point that was measured. It works...sorta!
I found that if there is more than .005 runout, it can be tricky to get it to less than .002 and I sometimes can't get it straight at all.
I've got a LE Wilson seating die that uses an arbor press coming in Monday. Hopefully it'll help...hopefully!

 

[64Rambler]

Assuming you have a decent quality FL sizing die, what do you do about brass runout if you encounter that?
Lets assume you don't have the funds to go out and buy a premium FL sizing die, you just have to try and make what you got work.

Have you checked the run out of fired brass? Start there and follow each step. You said you have a Forster FL die and Redding Bushing die. Compare the runout after sizing with each. You can still mandrel after a bushing die...

 

[Thor357]

Have you checked the run out of fired brass? Start there and follow each step. You said you have a Forster FL die and Redding Bushing die. Compare the runout after sizing with each. You can still mandrel after a bushing die...

Hmm...hadn't thought of that!
Great idea!
Will do it after today.
Thanks!

 

[358WCF]

I'm OCD so I try for high precision and accuracy every time I shoot.

Sorry, my OCDness won't let me stop until I've exhausted every effort. I've replaced barrels because of this not to mention a host of other things. I've made an expensive hobby into a VERY expensive one!

Here's a resource to really fuel your runout OCD, or even develop a whole new series of things to be OCD about. There was a guy named Merrill Martin who wrote a bunch of articles about "banana shaped cases" in the late 80s &/or early 90s. He also wrote extensively about cast bullets. Sorry I cant be more exact with the dates but dont feel like rummaging thru a pile of magazines right now. If you choose to look thru a few of the magazines, you'll likely find something beneficial. The best thing is it's free. Enjoy.

Internet Archive: Digital Library of Free & Borrowable Texts, Movies, Music & Wayback Machine

archive.org

 

[RB64]

Excellent advice! Thanks.
Here's what I'm working with. I use a Forster .308 sizing die.
I use a Redding single stage press (Rock Chucker, about 3 years old).
I have an LE Wilson mandrel die.
I'm using Starline Brass ( 6-8 firings).
Sierra Match King Tipped bullets.
A Forster micrometer seating die.
The seating die is flush to the press.
Shell holder has been cleaned as well as where it sits.
The dies have been cleaned.
I use Hornady Unique Case Lube (sparingly).
I don't have a nearby river to chuck a rather expensive (to me) sizing die into. And I'm not throwing anything away!
I just bought a Hornady Concentricity gage and on a whim I decided to check a few case for concentricity.
I only ran into this on about 6 out of 50 cases. Some had the body off by as much as .007 and or the neck or both.
The weird thing is they chambered fine and the bullets only had about 0.0015.
Should I focus on the runout of the bullets regardless of what the case shows?
How critical is case (body) runout to accuracy/precision?
Thank you for your time and expertise.

My experience. 2 things , Hornady , its indexing off the wrong points . You need one that index of the case body . Your die , its probably reducing neck down at least .010 and then you either using the sizer ball or a madrel to resize that neck which will cause bad concentricity . Send your die back to Forster and let them hone the neck to your specs there for you will only moving that neck .004 to .005 when you resize . Your brass will last longer and better concentricity. all my Forster dies are custom honed . Good Luck !

 

[K22]

I'm OCD so I try for high precision and accuracy every time I shoot.

Yep, I incorporate all this but with an LE Wilson mandrel.

My rifle is bedded.
This rifle has shot amazingly with other powders/bullets. I'm currently trying a different powder and different bullets. I'm on my 2nd try with this combo.

Sorry, my OCDness won't let me stop until I've exhausted every effort. I've replaced barrels because of this not to mention a host of other things. I've made an expensive hobby into a VERY expensive one!

Whatever floats your boat - go for it. No judgement from me, just sharing what I learned.

I too have been down a similar path when I competed. In the final analysis what really made the biggest difference was increasing my marksmanship skills through practice and more practice employing the fundamentals of marksmanship.

 

[Thor357]

Here's a resource to really fuel your runout OCD, or even develop a whole new series of things to be OCD about. There was a guy named Merrill Martin who wrote a bunch of articles about "banana shaped cases" in the late 80s &/or early 90s. He also wrote extensively about cast bullets. Sorry I cant be more exact with the dates but dont feel like rummaging thru a pile of magazines right now. If you choose to look thru a few of the magazines, you'll likely find something beneficial. The best thing is it's free. Enjoy.

Internet Archive: Digital Library of Free & Borrowable Texts, Movies, Music & Wayback Machine

archive.org

Oh man!!! Ha, I can't go look at this stuff!
I'll go batcrap crazy and if you've read any of previous post, you see that it's true!!!
I'm certifiable!

 

[Thor357]

My experience. 2 things , Hornady , its indexing off the wrong points . You need one that index of the case body . Your die , its probably reducing neck down at least .010 and then you either using the sizer ball or a madrel to resize that neck which will cause bad concentricity . Send your die back to Forster and let them hone the neck to your specs there for you will only moving that neck .004 to .005 when you resize . Your brass will last longer and better concentricity. all my Forster dies are custom honed . Good Luck !

Hmm...okay, maybe I will do as you suggest but something to consider.
Firstly, I have both a Redding S series bushing die and an LE Wilson mandrel die.
I mostly use the LE Wilson. I ordered an LE Wilson seating die that uses an arbor press too. It should be here tomorrow.
Secondly, I just resized some brass and I checked concentricity on them and they were damn near perfect!
Different brass and different bullet! So I'm confused but that isn't uncommon for me!
So I'm thinking you are probably most likely correct about my gage because so many people have said the same thing. So I'll look into another one and perhaps put my Hornady on the market place.

 

[kelbro]

Have you checked the run out of fired brass? Start there and follow each step. You said you have a Forster FL die and Redding Bushing die. Compare the runout after sizing with each. You can still mandrel after a bushing die...

I was just about to suggest that. Need a baseline.

 

[Thor357]

Have you checked the run out of fired brass? Start there and follow each step. You said you have a Forster FL die and Redding Bushing die. Compare the runout after sizing with each. You can still mandrel after a bushing die...

Not yet but I will. Thanks for the advice.
I went shooting yesterday and have "fresh" brass to do just that.

 

[kelbro]

Not yet but I will. Thanks for the advice.
I went shooting yesterday and have "fresh" brass to do just that.

That will help rule out a wonky chamber.

 

[Thor357]

That will help rule out a wonky chamber.

OH LORD!!! Please don't let it be a "wonky" chamber!!!!
I only have so long to live and barely enough money to make it that far!

 

[tdogg]

As many have already stated, I've been down this rabbit hole.

Fired cases should be straight, like broken indicator straight. Sizing is where the crooked necks get formed. The best bullet seating die in the world won't fix a crooked neck.

I'm not sure exactly how or why a straight case post firing can become crooked during sizing? My leading hypothesis is that during the brass forming/drawing step at the manufacturer, the case gets formed slightly off center and there is a thickness variation throughout the case wall. When you size it, the brass springs back at different rates around the circumference and causes the neck to deflect off center.

Even if you trim necks they still will have some deflection in my experience. I think it in the body and shoulder that cause the deflection.

SAC bushings seem to make straighter ammo and I think that is because they have a funnel design on the inner diameter of the bushing that minimizes the compression forces on the brass.

As mentioned, figure out which cases aren't straight, and mark them. If after the second firing/sizing cycle they are still crooked, cull them or use them for foulers. Premium brass makes straighter and less variable ammo. Starline is tough but not as uniform as some of the best on the market.

Cheers,
Toby

 

[tdogg]

Oh and ditch the Hornady concentricity gauge. Trying to straighten ammo will cause more harm than good. Neck tension uniformity is paramount to low ES ammo. Bending the case neck will change the neck tension and make your ammo worse off. Just track the cases that are crooked and cull them from your premium ammo components pile.

Cheers,
Toby

 

[DShortt]

OH LORD!!! Please don't let it be a "wonky" chamber!!!!
I only have so long to live and barely enough money to make it that far!

Since you have an aftermarket barrel, it's *probably* fine, but best to check and verify.

Particularly with factory barrels, I've found that there seems to be no end to the ways they can have problems. And I've found more than one aftermarket barrel with problems.

Again, the point is to trust, but verify. No point wasting your time and components on a barrel that's never going to perform well.

 

[Webster]

Assuming you have a decent quality FL sizing die, what do you do about brass runout if you encounter that?
Lets assume you don't have the funds to go out and buy a premium FL sizing die, you just have to try and make what you got work.

Your assuming run out is from a bad die. I would think they are made to about +/- 0.002".

When the bullet reaches the beginning of the rifling the chamber PSI is about 8000 PSI. This should make the case conform to the chamber. The forcing cone that the bullet passes thru before it hits the rifling land is only about 1 thou bigger than bullet diameter. The accuracy you need depends on what you’re going to use the rifle for. It takes a lot more than measuring a few things to make a rifle competitive. I only have to shoot about five shots to decide if my barrel has a chance at shooting under ½”. You have to decide what the rifle is capable of and l live with it. Reloading ammo only helps to a certain degree. You cann't make a factory rifle shoot like a competitive rifle by reloading ammo.

 

[DShortt]

Your assuming run out is from a bad die. I would think they are made to about +/- 0.002".

When the bullet reaches the beginning of the rifling the chamber PSI is about 8000 PSI. This should make the case conform to the chamber. The forcing cone that the bullet passes thru before it hits the rifling land is only about 1 thou bigger than bullet diameter. The accuracy you need depends on what you’re going to use the rifle for. It takes a lot more than measuring a few things to make a rifle competitive. I only have to shoot about five shots to decide if my barrel has a chance at shooting under ½”. You have to decide what the rifle is capable of and l live with it. Reloading ammo only helps to a certain degree. You cann't make a factory rifle shoot like a competitive rifle by reloading ammo.

The OP did state he replaced the factory barrel with a Criterion, but obviously that doesn't mean there is no barrel issue.

I'm guessing the 200 round outing yesterday didn't clarify much or he'd have posted results by now.

Maybe it's in another thread....... ?

It also sounds like the OP *may* be changing multiple things at once. I've never found that to be productive. Change 1 thing, test. Results unsatisfactory?
Change 1 more thing. Test.

Repeat as necessary.

If nothing seems to work, it's *probably* still a barrel issue.

But a rifle is a combination of components. If any one of them is not performing correctly, it'll show on the target.

 

[Thor357]

The OP did state he replaced the factory barrel with a Criterion, but obviously that doesn't mean there is no barrel issue.

I'm guessing the 200 round outing yesterday didn't clarify much or he'd have posted results by now.

Maybe it's in another thread....... ?

It also sounds like the OP *may* be changing multiple things at once. I've never found that to be productive. Change 1 thing, test. Results unsatisfactory?
Change 1 more thing. Test.

Repeat as necessary.

If nothing seems to work, it's *probably* still a barrel issue.

But a rifle is a combination of components. If any one of them is not performing correctly, it'll show on the target.

I only was able to shoot 50 out of the 200 and each 50 rd batch was testing different things. The one I shot was an attempt to duplicate a previous batch from about 3 weeks ago and it did pretty much the same.

Yeah, you're probably right, sometimes I do try too many things at once but not this time.

This rifle has performed amazingly at times with different bullets/powder/brass and primers and I've made note of those times. This is new bullets/powders/primers but same brass I've been using for awhile (Starline). I'm just trying to see if this powder/bullets work in this rifle. It seems to...sorta.

The barrel has just under 3000 rds through it and with varying powders and bullets that do work to my satisfaction, this combo is a work in progress, maybe not much more progress though.

 

[DShortt]

I only was able to shoot 50 out of the 200 and each 50 rd batch was testing different things. The one I shot was an attempt to duplicate a previous batch from about 3 weeks ago and it did pretty much the same.

Yeah, you're probably right, sometimes I do try too many things at once but not this time.

This rifle has performed amazingly at times with different bullets/powder/brass and primers and I've made note of those times. This is new bullets/powders/primers but same brass I've been using for awhile (Starline). I'm just trying to see if this powder/bullets work in this rifle. It seems to...sorta.

The barrel has just under 3000 rds through it and with varying powders and bullets that do work to my satisfaction, this combo is a work in progress, maybe not much more progress though.

Curious - why are you just now looking at run-out?