I just got my nifty RCBS case master runout gauge today, I then proceeded to measure 22 of my best handloads for my favorite rifle, 16 measured .003 or less a few where in the .0015 range or less range. 6 measured .004 to .005+ with one going .007 total runout. I feel like I am getting anal and the amount of time spent to make one round is getting up there, so my question is how different will a .0025 runout cartridge shoot compared to a .005 runout one, what kind of difference will this cause

Per the NRA and US Army in the A A Abbatiello 1960 article "Gauging bullet tilt", match ammo is most likely to be .002", while service ammo is likely to be .0025".
For a 1 in 10" twist 30-06, the math and the experiment agree .001" causing .55" extra group size continuing to .004" causing 2.2" extra group size. Beyond that, the chamber bends the cartridge straight.

OMHO, .262" neck 6mmPPC chamber is going to bend the cartridge straight long before it has .004" eccentricity.

What does it all mean?
The tight chambers will bend the cartridge straight. SAAMI chambers have .004" of space around the neck.

If you have .007" runout, don't worry, you will shoot as well as the guy with .004" runout.

Not for me I loaded 10's of thousands of rounds and never checked one for run out.

My guns shoot for me or they go down the road if I can't find a load the does.

I don't turn necks, check flash holes for size or other things bench rest people do.

I do hve several varmint and big game rigs that give me very good results. Some .5 or better quite a few under 1 inch. the rest are min of what ever too how far I want to shoot with them.

Some I wouldn't shoot over 100 yards others way out there. Most well kill when and where I want them too.

Check all the stuff you want I have better things to to with my time.

I feel the same. My rifles shoot 1/2" and better and one shot .200 last week and I never check runout, don't weigh brass, don't turn necks and don't debur flash holes. For a very serious BR shooter some of that stuff may make a difference at 1000 yds but it is a waste of time for me and my stuff shoots good. If you have lots of time to waste then go for it.

Hey c c

Those readings are pretty typical of a loading.

Were you measuring on the bullet ogive?
What caliber is this and what kind of brass?
Were these loaded with that bushing die you just got?

Use the RCBS tool to setup your press and dies for less runout. If it still bothers you the Bersin tool will adjust loaded rounds for you. It has made a difference in my ammunition, most of the best groups I've shot have been with rounds ajusted to less than .0012 runout....................DJ

The Japanese made laminated swords with rituals.

My guess is that those, who get great groups and don't check concentricity, have loading rituals that make concentric ammo.

I started out with 6" groups and now I have a couple rifles that have done groups less than .5".
Concentricity was a big part of the improvement.

I don't have to keep measuring concentricity to keep the quality I now have.
I just follow my ritual.

I never check runout, don't weigh brass, don't turn necks and don't debur flash holes just like dwight, half the time i dont bother trimming the cases. just resize and debur the case mouth and clean up the primer pockets. my cases are miles off being to long so im trying to let them grow. yet i still get .5" 3 shot groups @ 100 with a factory rifle.

anyway once yourve found out you have a big run-out. what are you going to do to fix it?

quote:

Originally posted by djpaintles:
Use the RCBS tool to setup your press and dies for less runout. If it still bothers you the Bersin tool will adjust loaded rounds for you. ...........DJ

This is the advice to follow.

The runout you are experiencing is coming during the loading processes which you are employing. If the dies and methods are capable of less than .002 runout, then they should be doing it all the time. I only spin the rounds for my 6 PPC - BR rifle, but use it to learn what does and doesn't work.

the main reason I got the tool is to make sure I am loading consistant stuff, I tested it on 22-250 WW brass and loaded with 50 grn vmax bullets, I measured the bullets for runout and set the indicator about 1/10" ahead of the case mouth. this could very well explain why I get 2 shots together and 1 flyer, because roughly 1 in 3 loaded rounds where more than the .003 limit, no these where not loaded with my new bushing die, I am hopeing that comes in tomorrow, I can't wait to use it.

for reference I checked some black hills 50grn vmax reman ammo of which I have long considered to be the finest factory stuff out there. runout readings of .007 or more where common, in fact out of 20 tested I only got 4 that where under .004. this is the reason factory ammo just can't shoot as well as hand loads.

Cummins Cowboy

Yes one of the reasons that factory ammunition doesn't seem to give the same level of performance as handloads is their method of production induced errors or faults, which of course include "runout." When using your dies, either the new or the old ones, check the runout on the new or fired cases and then again after each reloading stage. Find out where the runout is occuring. What you will do next is to try to index the die body in the press so that a minimum of runout will occur at that stage. Bushing dies are great for 2 reasons (and maybe more.) If left with a slight freedom of axial movement they can size in a very concentric manner. The second and equally important thing (IMHO) is that they can be used to not overly size the neck. This makes the bullet seat with less stress and therefore less chance of introducing "runout." When developing a personal loading method I would suggest that you look at and analyze each facet or factor of the process and consider what occurs, and what you can control. Obviousily some factors such as powder type and charge will have a major impact on the results, as primer choice or brass manufacturer will have a correspondingly minor one in comparison. The way in which you work your brass and the alignment of the bullet to the bore will add it's own affects to the mix as well. May this be of some use to you. Good shooting and fun loading.

I got a Sinclair concentricity gage in 2002.

a) It showed me in minutes that I did not want to pull an expander ball through a neck.

b) It showed me in minutes that I wanted a sliding sleeve seater.

In 2007 it showed me that
c) I did not want to use a Redding FL "S" die with floating bushing, but rather a Forster FL die with special order factory lapped neck.

That is about 10 minutes of good use in 5 years.
The rest of the time it was just G-whiz fool'n around, "Look how concentric the Greek military ammo is! What's wrong with the Federal Gold ammo?"

I have a gauge and set my dies to make good ammo. If I'm going on a hunt where long range shooting might happen I do sort my ammo to stuff that's under .003" even though I don't think my rifle can recognize any difference in ammo that's under .005". I have adjusted my dies and rarely get a loaded case over .003". I know a famous rifle maker in Texas that has built alot of custom rifles and alot of guys in my area have them. I asked him his take on runnout and he said for his own purposes he also tries to make ammo under .003" but doesn't sweat anything under .005. He said over .005" you could probably tell a difference.
Here is also a good "test" where a tactical shooter does a basic reload without fancy procedures and goes out and shoots a 2.5" group at 500 yds.

http://www.snipershide.net/forum/ubbthreads.php?ubb=sho...575&page=1#Post45575

Black Hills match ammo isn't known for fantastic runnout but in a good gun will shoot circles around alot of reloads. I still believe that 98% of your accuracy comes from the preference of your gun to bullet, powder charge, and seating depth. You may be able to improve it just a tad by doing great runnout but not nearly to the effect of finding a load and bullet your barrel likes.

quote:

Originally posted by tnekkcc:
I got a Sinclair concentricity gage in 2002.

a) It showed me in minutes that I did not want to pull an expander ball through a neck.

b) It showed me in minutes that I wanted a sliding sleeve seater.

In 2007 it showed me that
c) I did not want to use a Redding FL "S" die with floating bushing, but rather a Forster FL die with special order factory lapped neck.

That is about 10 minutes of good use in 5 years.
The rest of the time it was just G-whiz fool'n around, "Look how concentric the Greek military ammo is! What's wrong with the Federal Gold ammo?"

Maybe I never have a runout issue is because of what I use. I have both Redding bushing dies and Forster competition dies and seaters. I just got lucky with my routine and equipment to eliminate problems that others experience. I never heard of runout til I joined this forum anyway and I have always shot tight groups. Just plain lucky or just have the right tools to assemble my rounds.
I did not mean to throw darts at anyone but this runout thing is a non issue for me and I believe anyone that has the problem can get rid of it in their processes and tools.

quote:

Originally posted by tnekkcc:
My guess is that those, who get great groups and don't check concentricity, have loading rituals that make concentric ammo.

Exactly......that is why one person swears by FLS or partial FLS, while another swears by NS only.......why some ONLY weigh charges and others ONLY throw charges........

As long as you do exactly the same for every round you make, you will be consistent....

Hey there Cowboy since you got the new toy and have already identified quite a bit of difference in some of of your hand loads how about doin a test? I for one would sure be curious as to how much difference it makes. Course the weather in my part of the country is sure not conducive to shootin right now and I doubt it is in Utaw either. If some one runs a test I sure hope they report back on results
Wayles

tnekkcc
Would you mind expandin on your first 10 min of lernin about not pullin an expander back thru the neck .Did it pull the shoulder back out or whut.If you don't mind expand on the rest of your statments also and what equip you recommend and why . Tryin to learn something here.
Thanks Wayles

To those of you who say you don't worry about runout and still get good groups: Can you really know for sure you wouldn't be shooting even better groups if you never try shooting ammo with very low runout?............................DJ

Just got the new "Shooting Times" for this month. Will "expound" after a closer "reading". But, they are testing a new
Savage factory rifle in .308. This gun shoots EVERYTHING at under MOA to 500 yds. Many groups at under 2" (at 500 yds). NOW being that all the "runnout people" are saying that bullets are distorted by going into barrels "crooked" and the barrel will never correct the situation are (I believe) about to be disproved.

Will report more tommorrow after re-reading said article. (several times)

Wow---what a gun. I'm thinking Savage did a hand pick for this article. I wish the article had a little more info on the ammo. Basically 7 different ammo loadings shot under 2" at 500 yds. The factory ammo by black hills, hornady, corbon etc shot everybit as good as any of the hand loads. They said that handloads were loaded with "normal dies" paying no attention to any specific details other than seating depth and overall cartridge length. One batch of ammo went in .88....at 500 yds.
For me this pretty much settles the argument that ammo does NOT have to be .002" and under to shoot match quality as I've seen plenty of posts about the runnout on even the "match grade" ammo from the major manufacturers in this market. I would have to say that a good barrel does straighten out that bullet as it goes down the tube.....and bullets are not distorted by entering the rifling with runnout in place...or at least if they are it doesn't matter on a flight path to 500 yds.

Kraky, Your assumptions here are false. You don't now the runout of the ammo they shot in this rifle unless they measured it. Maybe the chamber was particularly tight and "straightened" the ammo as it was chambered. You shouldn't automatically make assumptions based on what you don't know. Just because certain ammo shot well in this rifle doesn't mean that it will shoot as well in any other rifle.

It was pretty outstanding results for a factory rifle though wasn't it. Don't know that I'd want to hunt with a 30" barrel though...............DJ

djpaintles,
You stole my thunder

wayles,
There is a little piece of paper, like what comes in a fortune cookie, that is in the box with a Sinclair concentricity gage that says something like, "You will probably find the expander ball is causing the problem."

That is one time my fortune cookie was right.
Take fired brass.
Check the run out at the neck relative to the body.
It is less than .001".
Put lube on the case and in the case neck, size the brass with a FL die with expander ball.
Measure the runout.
It is more than .004"
Take the decapping stem out of the die.
Size some more fired brass.
It measures less than .001"
Load some ammo from each of the two processes.
Measure the runout at the bullet ogive.
The crooked neck causes a crooked bullet.
Shoot the ammo.
The concentric ammo makes smaller groups.

Why is the expander ball causing the neck to bend?
When the expander ball goes in, the neck is big.
Then the die sizes the neck.
Now when the expander ball tries to pull out, the neck is tight.
The neck can be expanded or contracted .001 to .002" and spring back without taking a set.
The the expander ball to neck inside diameter interference is more that that. That is why the ball is there, to get the inside of the neck stretched out to bullet size, and then have it spring back to smaller so it grips the bullet.
The expander ball pulls through the neck and is pulling against a shell holder. This shell holder does not constrain the direction the neck is bent.

If one sizes the brass without an expander ball, and then uses the expander ball, the brass comes out much more concentric. The pushing seems to work much better than the pulling. But there is still SOME error from the process.

I have never found a jacketed bullet yet, that I cannot seat without using an expander ball.

Getting the brass deprimed without the expander ball sometimes means using a decapping die, or a smaller expander ball from a different caliber.

Getting a cast bullet to seat is what Lyman M dies are for. They open the neck and put a flare at the top.

DJ--I can almost guarantee that ammo was not much more concentric than any other factory assembled ammo. Hopefully someone will chime in here who has run some of this "match" ammo across a gauge. It would not surprise me to see that many of the rounds had .004, .005 and more runnout. There are so many manufacturers involved in supplying the ammo for that test and with no special reloading techniques applied to the handloads it's apparent to me that condition of ammo just didn't matter much.
I do agree that there maybe something about the gun that it just doesn't matter. I'm betting that gun was handpicked and sent to them by Savage and if someone "air gauged" the barrel it would rival any custom barrel out there.

Perhaps there is a chance that runnout affects different guns in different ways. To some it might matter....to the next it doesn't. We can all speculate all we want about how a bullet enters the rifling at the time of ignition.....if it's deformed at all....if it's corrected as it goes down the barrel. Until someone invents a camera that photographs the whole event and can follow a bullet down and out the barrel.....I guess we'll never know.

Really long and hard bullets, like black tip 30-06, don't care as much about concentric necks.
They work it out in the barrel.

On the expander ball and concentricity...

When adjusting the F/L sizer die allow the decapping rod to be slightly loose in the die body. When the case is being drawn out of the die and beginning to contact the expander ball tighten the lock rings to freeze the ball in place. The ball should be way more concentric with the necks if adjusted in this manner. You may not have to buy bushing dies after all!

After all good reloads are a matter of technique and knowledge.