Bullet run-out, how to fix it?

[IA_shooter]

Ok, so I've been meticulously (very meticulously) preparing my brass (once fired R-P) and my bullets (meplat trimming/weighing) and weighing my powder to the gnats @SS and get the bullets seated only to find excessive run-out in my bullets once all is done. Would this be due to variances in the thickness of the brass in the necks or my seater die (RCBS) being not quite right? I have 100 pcs of new Lapua brass I'm going to start using shortly and I wonder if the quality of the brass would make a difference? I'll have to load some of the Lapua brass and check the rounds for run-out I suppose. Should I be trimming the neck brass on all these cases to get a more consistant neck wall thickness to get better results? I just hate something not being PERFECT! LOL :

Thanks for any help.

Trevor

 

[Tim Singleton]

The lapua Will make a big showing right out of the gate.
I would suggest if your after that kind of precision send 3 fired cases to Harrels for a sizing die. Then buy a Wilson seater die

 

[Twud]

What do you consider excessive run out? I had a similar problem with my 6mm BR Rem. I started using a Wilson arbor seating die and the problem went away. The gun has a tight neck so all the cases had to be turned, I was using Lapua brass and the gun was custom built so I felt confident it wasn't the chamber. I was using custom match grade bullets made by smith that built the gun.
Anyway, I got the run out down to around .002" and it shoots unbelievably well. Little bug holes at 200 yds.
Oh, what neck sizing and seating die are you using?

 

[Larryh128]

You will never eliminate run out on brass that is banana shaped BUT what will help is seating the bullet about 1/2 of the seating depth, rotate the case 90 degrees & finish seating the bullet. This helps center or reduce the tilting effect of seating a bullet. It will knock off in a lot of cases about 1/2 of the run out. If you do this with the Lapua brass, you shouldn't see much.

 

[nosualc]

Ok, so I've been meticulously (very meticulously) preparing my brass (once fired R-P) and my bullets (meplat trimming/weighing) and weighing my powder to the gnats @SS and get the bullets seated only to find excessive run-out in my bullets once all is done. Would this be due to variances in the thickness of the brass in the necks or my seater die (RCBS) being not quite right? I have 100 pcs of new Lapua brass I'm going to start using shortly and I wonder if the quality of the brass would make a difference? I'll have to load some of the Lapua brass and check the rounds for run-out I suppose. Should I be trimming the neck brass on all these cases to get a more consistant neck wall thickness to get better results? I just hate something not being PERFECT! LOL :

How much runout are you seeing? Expecting -0- runout is not realistic. IMO, < .002" is good, < .001 very very good. Runout can be caused by many things, and chasing it down can be quite the journey.

What I would suggest to you is to measure runout on the case neck (and/or the case body) at every step along the way during the reloading process, and see where your runout is introduced.

For concrete suggestions, I'd start with good quality brass, which could very much make a difference. I don't think you need to turn your brass, but know that some bullet runout will be there due to varying neck thickness.

After that I'd say that most runout that I've seen or heard of is caused during the case sizing process (dies, lube, technique, etc). Last, look at inline seating dies (Wilson) with an arbor press.

It all comes down to how far you want to go down the rabbit hole. Good luck.

-nosualc

 

[Nodak7mm]

IA Guy,

HAve you checked your run out before you seat bullets to see if your inducing it with your sizing die or is it occuring after seating. Isolate the step that is causing it to determine which process step is causing it.

At the risk of advising something you may have already done/do, but are you using bush dies or sizing dies without the expander button....? Need to ask cause I did not see this info.

Rod

 

[Uthink Uknow]

Most important thing is, what is your runout on the target. Fire form those puppies with 50,000 psi and then check case runout.

 

[IA_shooter]

Thanks for the replies guys. I'll do what you guys are suggesting and maybe step up to the Wilson seater die as well and see if I can fix the issues.

Thanks again, I'll post my results if I can get it fixed.

Trevor

 

[ar10ar15man]

one guy pointed in the correct direction.
YOU HAVE TO KNOW THE SOURCE OF THE PROBLEM.
(if you only look at the end results, you do not know where the problem is)

WHAT IS THE RUNOUT OF YOUR FIRED BRASS ?

WHAT IS THE RUN OUT OF SIZED BRASS ?

and then wha tis the runout of the loaded round...

 

[IA_shooter]

one guy pointed in the correct direction.
YOU HAVE TO KNOW THE SOURCE OF THE PROBLEM.
(if you only look at the end results, you do not know where the problem is)

WHAT IS THE RUNOUT OF YOUR FIRED BRASS ?

WHAT IS THE RUN OUT OF SIZED BRASS ?

and then wha tis the runout of the loaded round...

I found the problem tonight, thanks to all you guys for the help.

The problem was in my RCBS FL sizer die. My runout in the necks on the brass I ran through my RCBS FL sizer was about .005. The runout on the necks of the brass I had fired and then ran through just the RCBS neck sizer die was only .001. I hadn't loaded any rounds in the brass I had fired in my gun and then just neck sized until tonight. The runout in the bullets using that brass was only .001-.002. vs run-out of .005-.006 in the brass I had loaded after FL die sizing.

Problem solved! I'm much happier now. ;D

Thanks again for the help guys.

Trevor

 

[BigDMT]

get a Redding Type S full sizer bushing die and you'll be even happier yet

RCBS has never been a favored brand in the precision reloading world, probably never will be. Neither will Remington brass...

 

[STS]

You may have solved only part of your problem. If you have the issue of OD concentricity of your cases under control, and you have not neck turned your cases, you will still have issues where it is most important, that is at the bullet. If the case neck is running true on the OD and the neck wall thickness if variable the bullet can't be looking down the center of the barrel which is the ultimate goal. The Remington brass is very likely to have neck thickness problems. Your Lapua brass will be better but not perfect. The next step in your road to perfection is neck turning.

 

[JDMock]

According to Mr. Ferris Pindell (of PPC fame), most runout is caused by the sizing die. Of course, the seater can also be the culprit. My advice is to lightly outside turn the brass (preferably Lapua) and fire form in your chamber before using it in a match. Good shooting...James PS- RCBS' new turner in action.

 

[BigDMT]

I just read all the reviews on midwayusa for that RCBS neck turning tool. Just as expected. Sloppy shell holder, set screws that eventually strip out, poor machining that leaves slop in the arbor, etc....

The reviews from folks who gave it 5 stars are obviously people who don't know what a good turning tool is. A neck turning tool is one of the things you don't want to spare expense on if you want repeatability and reliability.

Judging by the picture, it doesn't look like the case depth is adjustable. No mention of different cutters for different angles of shoulders either.

Turners that give the option for titanium nitride arbors are a very nice luxury. No lubing required for smooth operation. The RCBS does not offer that, which I'm not surprised.

 

[treeman]

it's my opinion that neck sizeing causes problems in the long run. you eventualy get to the point that brass will get hard to chamber (after 2-3 fireings) then you are back with the problem. IMO you should get a FL sizeing die that has a bushing so you can control the amount of sizeing done to the neck and bump the shoulder a couple of thousandths every reload and then you will have cosistent reloads for the life of the brass. also be sure that your expander mandrel isn't bent. it can pull necks off center.
good luck and good shooting

 

[JDMock]

BigDMT, I don't know about the shell holder since I am not using it. I chuck the brass in a drill and turn. The tool is adjustable for cut and depth. It is very well made and I don't know who gave the reports, but they are wrong. I also own and use turners from K&M and from Stiller. I have not stipped any set screws and the tool has worked perfectly. Yes, I do know what a good tool looks like and I have turned thousands of necks. Good shooting....James

 

[BigDMT]

James, I'll take your word on the RCBS trimmer. I hope it serves you well sir


I have a question for everyone with a neck bushing die; Why in the world do I constantly hear folks talking about using an "expander ball" on their neck bushing dies???
Sure they come with a de-capper and expander, but using a bushing to control and change neck tension to test accuracy is completely thrown out the window when they pull an expander ball through it. If they want to be able to de-cap at the same time as sizing (which I do separately), just put an expander in for a smaller caliber to hold the de-capping pin.

 

[ar10ar15man]

simply because it came that way....
if the maker sold it that way, it must be good to go.
WRONG..
using a bushing only die, either neck or fl, is common in br and competition, but not to everyone else.
used with neck turned brass or even cleanup cut brass..it works well. factory brass with factory chambers, its harder to see whats going on.
so they use it as is and tell others how great it is ..even if it is not.

James, I'll take your word on the RCBS trimmer. I hope it serves you well sir


I have a question for everyone with a neck bushing die; Why in the world do I constantly hear folks talking about using an "expander ball" on their neck bushing dies???
Sure they come with a de-capper and expander, but using a bushing to control and change neck tension to test accuracy is completely thrown out the window when they pull an expander ball through it. If they want to be able to de-cap at the same time as sizing (which I do separately), just put an expander in for a smaller caliber to hold the de-capping pin.

 

[BigDMT]

Yeah, that's what I thought :-\

 

[Joe C]

BigDMT,

Perhaps the answer to your last question lies in what drew me to this forum. I've been loading for about 20 years now. Roughly I have quite seriously loaded over 500,000 rounds, most of it pistol. I've gotten good enough results out of my rifle ammo for what I've done in the past but wanted better.

So I found this site and have been learning for the past year how much I DON'T know, especially regarding rifle loading. For example, just before reading this thread I read an email from Rod telling me to remember to take the expander ball out of my. 240NMC die. I simply didn't know that! But now that I do I have a new understanding of why not to use it and have put a .22 expander in the die so I can de-prime while sizing without messing up the sizing process of the bushing.

Knowledge is power and thank goodness for good folks on this site to help a person get more of it. ;-)