WHAT AM I DOING WRONG

[lrgoodger]

Use a shoulder gauge and measure base to shoulder length on a fired case, then measure it again on a sized case that has had runout induced. If the sized one is more than a couple thousandths shorter than the fired case, there is a good chance that is where your runout is coming from. I've found excessive shoulder push back to be the biggest culprit in causing runout. Some dies can be adjusted, some have to be carefully positioned in the press to avoid this issue.

Either that or you are sizing the neck down too much in one pass (as has been stated). Check to see how far down toward the neck-shoulder junction the bushing is being pushed. Even the highly touted Lee collet die will induce runout if the collet closes too close to the neck-shoulder junction. Anything that causes downward force on the shoulder is suspect.

I use a washer with the lee collet die to limit how much of the neck is sized to keep the collet high enough above the junction. My 6BR LCD yields impeccable runout using this method. My custom 30BR LCD does not do nearly as well, but I finally figured out that my Redding 30BR bushing die will yield straighter necks than the LCD if I position it in the press so that it does not fully size the case. I don't push the shoulder back at all until several firings make it necessary. Having the die up that far off the shellholder limits how much neck the bushing sizes, keeping it well away from the neck-shoulder junction. This has given excellent results.

BigEd is right on the Forster shoulder bushing bump die. I wasted my money on one before I figured out it pushes the shoulder back without supporting the case body. That simply causes case diameter to expand between the shoulder and the base as the shoulder is pushed back, and exercises NO control on keeping the neck straight.

And all that is simply addressing runout. Others are correct in stating that 3 - 4 thousandths runout is not likely to cause poor groups at 100 - 200 yard ranges, but I like to get variance in as many variables as possible minimized to successfully pin down the real problem.

Good luck.

 

[LRPV]

I bought a Wilson neck sizer for my Dasher so I could neck size cases that I pulled bullets out of quickly. All I know is, when I shake the one I have, the bushing rattles. Not much but it does. Otherwise, I don't neck size anything anymore.

 

[bigedp51]

I found out about the Forster die out of curiosity of just wanting to try one out. After seeing the results I bought after market Forster expander and spindle assemblies for my RCBS dies. And like the poster below I'm getting .001 or less neck runout with a full length resizing die. So my neck sizing dies are very seldom used with this kind results and minimum neck runout.

To the OP, read the entire thread at the link below.

Neck sizing causing runout.
Post # 36
http://forum.snipershide.info/showthread.php?t=262572

"My process is fairly simple. First, I shoot all new brass before I neck turn. A day at the range "fire forming" using all the leftover bullets (or the free ones I got from Hornady in their 'Get Loaded' promo) lets me make sure that the case has had at least ONE expansion cycle on it before cutting the necks.

I size using a Forster Benchrest Full Length Die and leave the expander ball in place. I then turn the necks using a Forster neck turning tool and holding the case in a sinclair case holder that fits in my cordless drill. A little "90 weight" applied sparingly to the mandrel on the turning tool keeps the case from transferring brass to the mandrel while turning.

I set my cutting depth so that I cut at least 270 degrees around the case neck circumference but no more than JUST 360 degrees. The idea is to make the neck uniform not necessarily thinner (unless you have a custom chamber that required a turned down neck). When I find a case that cleans up with 270 degrees of "cut" and leaves just scratches on the remainder of the case I use that setting for all cases in that batch (usually 100-200 cases in my "batch"). At this point it would be good to note that cases should be trimmed for uniform length so the neck turning is uniform in length as well (the tool has a stop on the mandrel). Over the years I've found that my Lapua brass ends up with .014" neck thickness and my Winchester with .012".

When finished neck turning I clean in SS Pins and when finished I anneal (Helps speed the drying process).

Once done this process is finished for the life of the case with the exception of continued cleaning and annealing.


As an added step I take the "batch" and then sort it into 50 round boxes by weight and try to keep that batch together through it's life. When primer pockets start to loosen or I then dump the "batch" into my box of "fun shooting" or "sighter/fouler" box of brass. That brass then just gets tossed out by the ejector and swept up at the end of a shooting session (or grabbed by the brass rats). I then start again with a couple hundred NEW pieces.

Note: The Forster Die I use has feature where the expander ball starts to expand the case neck while part of the neck is still in the sizing portion of the die. It matches the mandrel size on the turning tool and the runout measured on the case equals merely that of the case neck thickness variation. Near ZERO after turning.

There are several neck turning tools that work great but one of them IS NOT the RCBS Tool. Avoid with all possible effort. K&M, Sinclair, or Century 21 are great as is the Forster."

 

[Patch700]

You can play around with runout numbers till the cows come home... The proof is on the paper.

For all we know there could be an inherent problem with the measuring tool.. No sense pulling ones remining hairs out chasing a die problem when it could be the way in which the cases are being measured.

My take on it is this... If being 100 percent concentric was paramount then you would think that straightening loaded rounds would show an improvement... I think most of us know what happens when you try to straighten ammo...

 

[dipstick]

First let me thank everyone for their input.

While I haven't tried everything that has been suggested let me answer a few of the questions.

I measured some fired cases and may be trying to size too much in one step (fired case .254 sizing to .248). May be a problem.

I don't have a shoulder gauge, I may be moving the shoulder with my neck sizing die. May be a problem.

I used sizing wax on the necks only after I tried them without any lube. I thought that I felt the case "drag" in the die. The results were essentially the same each way.

I left the bushing slightly loose in the Wilson die and tightened it as tight as I could with the "cap". The results were the same.

I only shot 1 group each sized with each die. The full length sizing shot better, but it was only one group each.

I have decided to shoot three groups each with the two different dies and compare all of them. Hopefully one will show a significant improvement over the other.

There are several other potential reasons why I have this problem.

1. I just may not be that good of a shooter.

2. This may be all this rifle is capable of.

3. I may not have tried the right combination yet. I have only tried 53 gr SMK's and 50 gr VMax.

I have prepped the cases and will continue the journey.

 

[South Pender]

First let me thank everyone for their input.

While I haven't tried everything that has been suggested let me answer a few of the questions.

I measured some fired cases and may be trying to size too much in one step (fired case .254 sizing to .248). May be a problem.

I don't have a shoulder gauge, I may be moving the shoulder with my neck sizing die. May be a problem.

I used sizing wax on the necks only after I tried them without any lube. I thought that I felt the case "drag" in the die. The results were essentially the same each way.

I left the bushing slightly loose in the Wilson die and tightened it as tight as I could with the "cap". The results were the same.

I only shot 1 group each sized with each die. The full length sizing shot better, but it was only one group each.

I have decided to shoot three groups each with the two different dies and compare all of them. Hopefully one will show a significant improvement over the other.

There are several other potential reasons why I have this problem.

1. I just may not be that good of a shooter.

2. This may be all this rifle is capable of.

3. I may not have tried the right combination yet. I have only tried 53 gr SMK's and 50 gr VMax.

I have prepped the cases and will continue the journey.

Just a couple of points.

1. I don't see how the Wilson neck-sizing bushing die can possibly move the shoulder back since it sizes only the last 3/16" (.1875") of the case neck, leaving an expanded neck between that point and the neck-shoulder junction. The 222 Rem. has a neck length of about .31", so the bushing will not be getting anywhere near the shoulder.

2. Comparing one group with one other is just not going to reveal anything useful. As an example, an average group size for Load A of .50" and an average group size for Load B of .75" will not represent a statistically significant difference with fewer than 10-11 groups shot with each load. Any difference between just two loads (or sizing procedures) will likely be nothing more than sampling error. Even the three groups per condition (sizing procedure) will yield a difference with too much sampling error to be anywhere near dispositive. This is the sad truth--basic inferential statistics.

I do like the idea of sizing down in two steps. I hadn't read about that, but it makes sense. You could start with the .251 bushing and then finish up with the .248. I'm going to try that too.

I might add that I was particularly interested in this thread because I too have just purchased a new Cooper M21 in 222 Rem. I haven't had it out to the range yet, but was planning a just-about identical set of loading steps as described in the OP. I too have started with virgin Lapua brass, trimming it, expanding it slightly with an expander mandrel and then turning it, using a 21st Century neck turning tool to a neck thickness of .0126 ± .001. I then trimmed it all again with the Forster 3-in-1 tool that trims and chamfers the inside and outside of the case mouths. I then sorted it, and described my experiences of weight-sorting in another thread on this forum wherein I explained my surprise at the variation in case weights of what is considered possibly the best brass available. Next step: priming, charging, seating some Berger 52-gr. match bullets, and then off to the range.

 

[22BRGUY]

On Wilsons I allow the bushing and the decapping rod to float by first snugging the screws down and then loosening them back about 1/8 turn. It seems to work beter for me on runnout.

 

[dipstick]

I think most of you are correct in the fact that the run out is not that important, at least in this rifle or most other production rifles. I shot several groups of each neck sized and FL sized. No noticeable difference. I probably didn't shoot enough groups to statistically significant, but enough to satisfy me.

South Pender,

I am sure your new Cooper will at least meet their 1/2" guarantee. Most likely better with a little load tweaking

Thanks to everyone for your help. I learned a few things.

 

[searcher]

I use a variety of bushing dies in different rifles, including the Forster, Redding "S" dies, Harrel's Precision and Wilson. I believe two of the possible causes are:
1) You are using too tight of a bushing and your cases are being tweaked. I have encountered this in many situations. Sometimes a load that shot real well goes to hell after annealing the brass - as the softer condition allowed the tight bushing that had been used previously with no problems to be too tight for the new level of annealing. Those cases DO move in those situations. Go to the lightest bushing you can and problem may very well disappear.
2) When you turned your necks, if you did so on an excessively loose mandrel, you could have very uneven necks that are much thicker on one side than the other. When sizing such necks, the floating bushing tends to induce runout as the brass will form to the weak side of the neck if there is any sideways play at all in the busing-to-die fit. A way to help remedy the effect of this is to re-turn your necks slightly smaller on a turning mandrel that has not play between the neck and the mandrel, then go to a slighlty smaller bushing if found to be needed.
Those who think the cases will not be made crooked by using too tight of a bushing would be surprised. Regardless, a few K in runout will not prevent a gun from producing the type of accuracy you want for an accurate varmint rifle (like 3/8 MOA in my mind). If the gun won't do it - it is not likely a result of this runout. I'd change powders, bullet or depth.

 

[dipstick]

Searcher,

I am sure neck sizing in two steps may help, but it seems a little run out may not make much difference. I will buy another bushing and try it the next time I order components or parts.

I turned the necks with a "tight" mandrel, and don't see any measurable variation in neck thickness.

This rifle will already shoot 3/8 and shows promise of more with some other powders. I am out of H335 and can't find any right now. Some loads with H335 looked better. The 53 gr SMK's with H322 seem to shoot ok. My first results with VMax's were a little disappointing and started this whole concentricity search.

 

[Gabe22BR]

If the rifle is a Cooper, it's not worth the trouble to "neck turn" the brass. The chamber isn't that tight, since they have used that reamer for numerous others. I have a rifle listed that has a 1.690 chamber length in 22 BR, bought this year. Cooper has "old" reamers for when they made the brass from 308 Palma, back in the day., as for the concentric reloaded shells in 223. use a f/l no bushing die, and a regular seating die, and go shoot.

I have duplicated my Cooper target @ 200yds with a regular Redding dies.

 

[CatShooter]

If the rifle is a Cooper, it's not worth the trouble to "neck turn" the brass. The chamber isn't that tight, since they have used that reamer for numerous others. I have a rifle listed that has a 1.690 chamber length in 22 BR, bought this year. Cooper has "old" reamers for when they made the brass from 308 Palma, back in the day., as for the concentric reloaded shells in 223. use a f/l no bushing die, and a regular seating die, and go shoot.

I have duplicated my Cooper target @ 200yds with a regular Redding dies.

Surely, you are kidding - that is 15+ years ago.... just how long do you think reamers last??

 

[Gabe22BR]

Surely, you are kidding - that is 15+ years ago.... just how long do you think reamers last??

How many Cooper's have you seen in 22BR?????????? think about it...... in popular calibers ....guessing~~~ reamers made last week. Maybe I should have worded it different.