I finally got a runout gauge and am astounded to discover 0.005+ bullet runout in a number of my loaded rounds.
Now that I've discovered the problem, how do I fix it?
Thanx,
R-WEST

What brand of dies do you use?

Is your sizer die adjusted properly? Mine wasn't and it caused me a severe amount of grief.

Are you full length sizing or neck sizing?
ZM

R-WEST - This is the problem with hand loading and new tools. It�s like going to a psychologist for the first time, you never know you had so many problems.

Seriously, there are a number of culprits that can cause both case and bullet runout (two different things). If it is consistent across all your reloads then it is your press. If it is consistent only with one caliber, then it is a die. If you only find a few with runout, then it could be a dirty seater or a lose die, or a shell holder problem. Did you also check the case runout on the loaded cartridges that had excessive bullet runout? Are the case necks straight to begin with?

Soultions - If it is your press, get a new one.(Preferably a Redding.) If it is a die, check the locking collet/nut and replace with a new one. If it is sporadic, then you need to carefully inspect, trim, and measure all your brass, disassemble and clean your die(s) both seater and sizer (pay particular attention to your expander button, you may wish to polish it), inspect your shell holder, inspect your press ram for wear. In short, when you see bullet runout in only a few cases, you have a large number of variables to track down.

Other ideas - anneal your cases, use mica on the inside of the case mouth before you resize, attempt neck sizing only, get new brass, mark the cases with excessive runout - do they maintain the same accuracy of your other rounds? If you are not seeing any accuracy concerns, then don't worry about it.

Z

Zeke and ZeroDrift -
I use a mix of RCBS, Redding and Lyman dies. The press is a Rockchucker. The calibers I've noticed the excessive runout on, .284 Win and 7x57AI, I use Redding dies, which is pretty good stuff historically.

The dies are adjusted the same as all my other ones - in steps until I get to the point where the bolt closes with some resistance, then 1/8 - 1/4 turn more and lock it down. I don't know if that's considered full length or neck sizing, but, that's what I do.

I've got a lot more checking to do, because those are the two guns that I really have a problem with, so, they're the first ones I checked. I doubt it's the press, because so many of my other guns really shoot well, and they're loaded on the same press. I've been using the same procedures and techniques for 30 years, so, it's probably not there.

I'll keep digging.

Thanks a lot for your ideas.

R-WEST

Accuracy is elusive at times as we all have experienced. Mark your cases that indicate excessive runout. When shooting at the range, see how they group. Some guns are not sensitive to runout and you may be worried about nothing. OR, your accuracy problems could be resulting from other factors like bedding, scope, load development. I would suggest that you shoot across a chrono and keep records of the Standard Deviations in velocity. If you have low SDs but poor accuracy, consider another load, powder, bullet combination. If your accuracy problems can be traced to runout, then start culling rounds and brass.

Good luck....

Z

Hi all

Had the same problem recently when I started loading for my new 264Win Mag. Bullet runout in exces of 0.005. Have bought new Forster Bonansa dies. Tried to measure case runout, it was way of, turns out the expander rod is bent!!
In goes the rod from my RCBS 6.5x55 and voila! Bullet runout is now under 0.002!!

Simple solution to my big problem(finally!)

Bendtsen

R West,
Here are a couple things that have helped me out.
My Winchester .308 brass gives me much better concentricity than my Remington .308 brass. I've started outside-neck-turning the Remington brass, and it's improved. Wall thickness variations "push" the bullets to one side or the other if it's excessive.
I've installed 3/8" diameter rubber washers from faucet repair kits under the lock nut for the expander rod. This allows the expander to self-center itself in the case neck as it comes out, but still keep its adjustment.
When I seat the bullet, I seat it about half-way, then turn the case 180 degrees and finish seating it. I figure if it starts a little crooked, turning it may help straighten it out.
I sort the rounds from "most" runout to "least" runout, and shoot the "worst" first and save the "best" for last. Many times, I shoot the tighter groups with the "worst" bullets! No expectations, nice and relaxed, you know... Maybe there's less to runout than we think??
Regards, George.

You can check your loading at every stage with a concentricity gauge and that is what you should do.

First check your fired cases. If they are off, your chamber is eccentric and any other check is fruitless.

Then, size a case after removing the expander from the die. That will eliminate the expander and/or die adjustment. If you run into an off center case here, you need to check die or die adjustment by either loosening the lock ring, or inserting an "O" ring under your lock ring. If it's off at this stage it's very likely you have runout on the ram on your press. Most presses do. Manufacturing tolerances by all the manufacturers is plus or minus .005". You can correct this offset by sizing with two or three strokes of the press rotating the case either 120 or 180 degrees as you size. You can check this on your concentricity gauge. The engineering in the Forster Coax press eliminates this runout and these tolerance problems, but all other "C" or "O" type presses have it, unless you're lucky. I went through 7 presses, some with runout as high as .011", until I got the Forster Coax.

After sizing a case with no expander and checking, reinsert the expander and size another case. This is where most runout is introduced into the sizing process. Check runout of the neck. This can be corrected by polishing the expander, lubing the insides of the neck better, or by neck turning to make the cases necks more consistent and eliminating the erratic stretching of different neck thicknesses.

If you're still OK and concentric, go forward, seat a bullet and check again. Many times the button in the seater is shaped incorrectly for the bullet used and this will introduce runout into the seated bullet. This can be corrected in one of two ways. You can contact the die manufacturer and purchase the seater to better conform to your bullet, or you can partially seat the bullet and rotate the case either 120 or 180 degrees progressively as you seat the bullet.

You can eliminate much of the problem by using the Redding S dies, which eliminates the expander, and a competition seater die, whose seater button usually contacts the bullet below the meplat and gives a more concentric contact on the ogive.

Die adjustment can be very important and can offset any runout built into your ram, as can adjusment of the expander or the bullet seater. You can check this with a dial indicator checking both your ram, or the movement of the die as you size a case.

In old NRA tests they determined that cartridges for long range use (over 100 yards,) should be within .002" concentric. Each .001" runout over this .002" maximum causes a quarter MOA deviation in groups up to .005". Anything over .002" was designated as "short range" loads. After .005" runout, it didn't matter much.

Hope this helps. Bob

But back to neck sizing.

When you shoot brass in a bolt action (or other "block action" guns like a High Wall) you don't need to resize the whole case. The case is fitted ("fire formed") to the chamber of the gun you fired it in.

All you do is resize the neck of the case. This requires a neck sizing die. Although you can partially neck size by not coming completely down on the case with a full-length die.

Fire formed brass is usually more accurate than full length sizing. Also causes less wear/tear on the brass -- extends brass life.

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PowderBurns,

seeing as I'm asking a bunch of questions elsewhere I won't make out I'm an expert (cos I'm not!) but re neck sizing - I don't think it's allways all it's cracked up to be.

1. In a factory rifle the chamber is quite likely to be slightly eccentric. Unless you mark the position of the case at the point it was fired then by neck sizing it only and putting it back in a differing position you might be increasing eccentricity.

2. Not all brass can take neck sizing and extract ok in a bolt action rifle. My rifle will not extract neck sized Norma brass.

Do we sometimes get a bit hung up on the mechanics of reloading compared to effectiveness in the field? I found myself trying to improve on 5/8" groups with my 6 power scoped hunting rifle which is never used over 200yards! In doing so (different brass etc I got into a whole lot of problems which made me realise I was trying to apply some procedures from another discipline to something that didn't need it and couldn't even show any benefits had I achieved it.

That said I'm still after the perfect cloverleaf!

I've found I get the best smallest runout by using Lee Collet dies (neck size) and by running the case through the die twice, rotating it 180 degrees the second time. I keep runout within .002 by doing this.

I have found that the absolute, best way to eliminate runout problems is to buy a K&M arbor press and Wilson dies. They seem to me to be less time consuming and once you start loading like this, you never want to do it any other way!

I see a lot of votes for necksizing. However, as 1894 pointed out, there are drawbacks. If your cases aren't square before you necksize them, chances are slim that they are afterwards. By using a full-length die and bumping the shoulder back a thou or so (must be MEASURED with a comparator, not by the size-and-try method), you get the case formed after the die which normally ensures straightness.

If the ram in the press and the die threads aren't on-axis and parallel, necks could be pulled out-of-true when you extract the case from the die. Same if the die isn't squarely screwed down. A bent shellholder will affect it too, as will a bent or misaligned decapping/sizing rod.

Some dies have features that reduce the likelihood of ram/die misalignment affecting the straightness of the case, my Forster dies give me straight cases even if fitted in my badly bent Lee Challenger press - all other dies prefer the still-true Rockchucker. Wilson hand dies are very good too, and standard equipment for the BR crowd.

Another option is to index the cartridges and chamber them in the same orientation.

-- Mats

After sizing 109 '06 cases (same lot), I trimmed them with a Lee trimmer chucked in a 3/8" drill. As I trimmed them, I separated out the ones that showed little runout as they spun in the drill. I got 31 "good" cases out of 109. I will keep these separate and see if they reduce the fliers I sometimes experience. BTW, I only shoot cast bullets. Since I had good and bad cases in the same reloaded lot, I'm thinking it must have something to do with my resizing technique. I full-length size. Partial sizing has always caused me trouble and I haven't yet sprung for a neck die.
This has been a good thread for me. Thanks everyone.

Guys -
Thanks a million for all the ideas. I can see I've got some work ahead.

This forum has GOT to have the most, and most knowledgeable, shooters around.

R-WEST

Bob338 has given excellent advice as usual. I have achieved the least amount of runout while using the Redding S neck dies without the expander ball installed. Keep in mind, however, that your case neck wall thickness must be pretty uniform for these to work properly without the button. If you have a case with variations in neck wall thickness then you're going to have runout problems no matter now straight you get the outside of the neck. I've only used Norma brass so far with these dies. Norma generally makes very uniform brass. Other brands such as Remington or Winchester may require some neck turning for these dies to work. I say "may" because as I said, I don't have any experience using any other brand except Norma while using the S dies.