• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Concentricity woes...

Paul West

Private
Minuteman
Mar 31, 2010
13
0
55
Coeur d'Alene, ID
Guys, I could use some help. Reloading for a bone stock Savage 16 Bear Hunter in 300WSM. Using new Winchester brass (that's all I could find at the time), once fired in this gun, with standard Redding dies. I'm having to use Hornady Concentricity tool to fix nearly every completed round. The RO is as much as .005". In most cases I can correct to sub .002", but not always.

I am convinced something is not right in my sizing process. My process is as follows. Tumble brass, remove primers, clean remaining carbon on outside of necks with 0000 steel wool. Use a brass brush in drill to clean inside of necks. lightly lube outside of case with Imperial Sizing Wax (by band), dip necks into dry lube (Mica), blow off excess and attempt a smooth resize stroke.

I am bumping the shoulder .002 doing so by using a thin shim between the shell holder and die to properly square the die in the press. I tighten the die down when it makes firm contact. I have tried several ways to set the decapper/expander, but nothing seems to work well. I've tried locking it down after the pin ejects the primer. I've tried locking it down per the directions, which basically say just lock it down when the pin sticking out the bottom by "X" amount. I've tried locking it down as I expander passes through the neck. Even with the dry lube it is difficult the lift the handle. FYI, The dry mica is 15+ years old, but it should be fine right?

Now getting the expander to pull through smoothly is nearly impossible. I polished the stock expander ball with chrome polish and I can almost see my reflection is it so smooth.

What is you technique to set-up the sizer die to make straight necks?

Sometime the shoulder get tiny little kinks, like I'm using too much lube, but I don't think i am. I think the stress of lifting the handle is doing this. I'm so frustrated. I wish I had purchased a different concentricity tool so i didn't have to load the case to check RO.

Thoughts?
Replace with Carbide Expander?
Bent Decapper/Expander rod?
Bad Lube?
Bad die?
Excessively thick necks?
Bad reloading?

Thanks.
 
Re: Concentricity woes...

I'd say its your dies probably more so your seating die. I use a forester bench rest die set or a lee collet with forster seating die and get consistently about .002 of runout. With rcbs and lee die sets .008 was not uncommon.
 
Re: Concentricity woes...

Thanks for the input. Big differences between the Forester, RCBS and Lee dies.

I've noticed the expander rod is always centered in the die which seems like a problem. This is the reason I've tried so many different ways to center it besides just tightening it's lock not. Should I be calling Redding?
 
Re: Concentricity woes...

First off, measure the run out of a fired but not sized case. Measure at the case neck obsiously. Note down the measurement.

Now size that piece of brass and measure. If the runout has gone up, the die is your problem.

It is common, and perhaps standard, for an FL die to do this.

It pains me to say this but the easiest way to avoid runout like this is to remove the expander and move to bushing dies. You will need to use good brass with consistent neck thickness otherwise you may need to turn.

The idea is to GRADUALLY size the neck down using only bushing, by 2 seperate sizing stages. The easiest way to do this is to get a Redding Bushing FL die, and a Redding Bushing Neck sizer. Remove the expander assembly from the FL die first. Put the larger sized bushing into the neck die, and slightly size the necks first. Next do the same but with the FL die, bumping back 0.001-0.002 and bringing the necks down to the final sizing diameter. The key is to size no more than 0.005 at a time, hence the need for a dual bushing setup.

A die set up like this is costly, and will run you over $200.

To determine bushing sizes, measure the neck diameter of fired cases, and subtract 0.005 and thats the size of your first bushing. The next bushing size will be the neck diameter of a loaded round (with the brass and projectiles you intend to use) and subtract 0.001 for proper tension.
 
Re: Concentricity woes...

Glad to see you have a concentricity gauge! You need to apply a Quality Management process for a while to track the problem

Measure everything step by step in the process for a while and see where the problem pops up. Then it is a case of working out why. I would think twice about calling the guys at Redding until you have narrowed it down a bit? Once you can give them a better steer as to the problem they will be able to help.

Expander balls are a pain. I had this sort of issue and have never used a die with one again.

I was running a process like this for my 308 and had runout variability. I spoke with the guys at Redding and we sorted it by making sure the inside chamfer was substantial. You live and learn. Without measuring step by step and input from Redding I would never have got there.

Body die, Bushing neck die and a Competition seating die would be my recommended kit for the levels of runout you are looking for
 
Re: Concentricity woes...

Shit can the Hornady tool, its a POS, I have a Sinclair and when it reads ZERO, the Hornady would read .003 or more on the same round, the Hornady only measures loaded round runout, with Sinclair type gauge a reloader can check each stage of the reloading process to see where the run out is coming from, a fired case prior to resizing with run out can not be fixed, get a new chamber.
 
Re: Concentricity woes...

Decap as a separate operation. Lee makes an inexpensive die for this.

Do not use the expander button.

Clean inside necks with a nylon brush.

FL resize with Redding S type bushing die.

Do not 'fix' completed rounds with that Hornady tool. It will induce neck tension inconsistencies. Get a better tool for measuring runout. Sinclair and 21st are two good ones. Measure along your reloading process. You'll find the problem long before you have to fix anything.
 
Re: Concentricity woes...

Thank you very much for taking the time to respond and offer help!

VMAN - My Hornady tool doesn't allow me to do check an empty case only loaded. It sounds like I should first invest in the Sinclair or Hornady tool? I am eager to try my hand at putting a bushing die to work and turn necks, BUT (don't hate) I will eventually be crimping these hunting loads. It seems like alot of work to manage the neck tension to then crimp. I will start with a new tool.

Chanonry (Andy) - Clearly a new C-Tool will is in order. I cannot track step-by-step until i make a purchase. Queation - have to tried the carbide expander? I'm using Lyman's VLD tool, but I will take a deeper cut. Can't hurt right?

427Cobra - I promise to never use Photobucket :). NEW TOOL!

Leaddog - decap as separate, been doing that, got the Lee die. I will look into new dies as soon as i decide on a new tool. Thank you for the tip on 21st Century. I had not seen this tool before. I will strongly consider it. Thank you for your military service; my family appreciates it!

To all: Is that a big no on the RCBS tool? I am simply passionate about making accurate handloads and knowing the capabilities of the ammo, gun and shooter (me). Am I making too big a deal about this? Since this is a hunting gun, what effect will say .004" RO have on accuracy out to 400 yrds? Will I see any effect at 100 yds (max at my local range)?

Thanks Again...
 
Re: Concentricity woes...

How does the ammo shoot at the ranges you need to shoot it at?
 
Re: Concentricity woes...

New gun, new everything. I have not fired the brass a second time. The best "potential" (ill explain in a minute) load was with new Winchester brass, resized due to dented mouths, Federal Match Primers, de-burred flashholes, zero bullet jump, 65.5g of AA4350, 180g Nosler BT. No crimp.

I broke in the gun prior with 20 rds.

Here's the data:

1 - (the flier) RO=.003 corrected to .0015, 2918fps
2 - RO=.0025 corrected to .002, 2863 fps
3 - RO=.0035 corrected to .0015, 2860 fps
4 - RO=.002 no correction, 2862 fps
5 - RO=.003 corrected to .001, 2861 fps

2862 average of the bottom 4 shots with only 4fps spread!

The grouping of the 4 was one ragged hole measuring .45" @ 100 yards. The flier was crazy .75 high and almost 2" left.

The next 5 shots at 66g of AA4350 were good as well (similiar ro to above) averaging 2881 w/16fps spread of all five and a cluster of 4 shots in .625" and a flier making it .875"

All loads before and beyond were not great (1" to 1.25"). Primer flattening started at 66.3g. There was little benefit in speed out to 66.9 (max was 67g).

If your curious:

66.3 - 2900fps avg and 45 fps spread (1.25" group)
66.6 - 2900fps avg and 16 fps spread (.875 group)
66.9 - 2890fps avg and 23 fps spread (1" group)

It was apparent the 65.5g was a very nice load for this hunting gun (21" barrel + 2" brake). I want to the look for a powder option that will get rounds this short barrel to 3000fps (again hunting gun), but I want the accuracy of the 65.5g AA4350.

Note: i have not duplicated this accuracy load.

So, the whole reason for the post is the RO of the resized cases is worse than the factory (resized). I fear the RO will not allow for me to duplicated and confirm.

Thanks!
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: loaded4deer</div><div class="ubbcode-body">Thank you very much for taking the time to respond and offer help!

Chanonry (Andy) - Clearly a new C-Tool will is in order. I cannot track step-by-step until i make a purchase. Queation - have to tried the carbide expander? I'm using Lyman's VLD tool, but I will take a deeper cut. Can't hurt right?


Is that a big no on the RCBS tool?

I am simply passionate about making accurate handloads and knowing the capabilities of the ammo, gun and shooter (me). Am I making too big a deal about this? Since this is a hunting gun, what effect will say .004" RO have on accuracy out to 400 yrds? Will I see any effect at 100 yds (max at my local range)?

Thanks Again...</div></div>

I just binned the expander as I took the view (rightly or wrongly) that there are now better ways and it was just one more thing to go wrong.

I take a deep cut for a chamfer!!

Nothing wrong with RBCS kit.

Will you see the effect of .004 thou runout at 400 or 100 yards? It depends on the other elements of accuracy in the 'chain'. If the 'rest' (rifle, you, support, powder etc) is capable of 1/2 moa then yes you may well. If it is only capable of giving you 1-1/2 moa then the error will get lost.
 
Re: Concentricity woes...

I have had odd issues with VLD neck chamfer cutters..If it isn't the seater I would look here first.
Lot of benchrest shooters use the RCBS cutter.

A few guys here claim to have cured a Redding runout issue with the carbide button (perhaps some of them can chime in here), but I have not been so lucky. I do think it worth a try.

I really like the custom ground and sized Forster seater route (no expander ball). To date it has given me my straightest ammunition.

All that said let me be straight.
Unless you can consistently shoot into 1/4 inch or so I think you will have problems showing any improvement in accuracy by reducing runout below 5thou....
Just so ya know before you spend your hard earned money
smile.gif


 
Re: Concentricity woes...

Good discussion. OK, so I called Redding. I explained the info above and their response was ".005 that is very very good." I was taken back and speechless. He explained that Redding's position is that concentricity has little effect on accuracy. Few benchrest people are concerned with concentricity. Hence, Redding does not make a concentricity tool. I explained that I've been chasing this sub-.002" number. We discussed the "S" die and carbide expander. He offered to replace my expander and/or polish the existing expander. Also, he offered to check and polish my die for free. Great customer service. To prove his point, he suggested taking really very concentric rounds and against very non-concentric rounds. He said you will be hard pressed to see a difference. I told him I would do the test before sending anything.

Redding said he thought there might be some concentricity correction once the round enters the chamber. Interesting thought. He did not have any supporting examples.

Redding feels much more accuracy is gained in the area of neck thickness. He suggested I sort brass by neck thickness. Anything over .0015" be set aside. He suggested Norma brass for the 300 WSM. Also, he did not suggest neck turning because the feeling is, if the neck is thin, the body is thin in the same areas and could present split case issues.

I had to share that in time I would be crimping these loads and I got an "oh...".

At the end of our conversation, he asked me to measure the expander ball and it should be .001 to .0015 below .308. I haven't measured it yet. He said it is a possibility the expander was mixed-up during assembly.

I still think I am going to get the Carbide expander (can't hurt) and do the accuracy test he suggested. Redding said the expander helps with reduced friction and it floats. It also fits the "S" die...

X-fan...what is the deal the "custom ground and sized Forster seater"? I have never been able to shot any of my stock hunting rifles (.243, .270, .300) into a 1/4 group. I can manage 3 of 5 into into 1/4, but never 5 of 5 with any consistency. This is probably what Redding is taking about. I appreciate your candor.

Paul
 
Re: Concentricity woes...

I run the Redding with the carbide 'floating' expander. Runout went from ~.004 to ~.002 based on that change alone. Also, I found the redding seating die fits my A-Max's better than SMK. A-Max is between 0 and .002, SMK is .002 - .003. I have not tried custom grinding a seating stem to fit the SMKs but I might. YMMV
 
Re: Concentricity woes...


I here you man, most people are shocked when they get the straight goods from Redding...Lot of here say second hand BS gets thrown around..Careful what you swallow.

For a hunting rifle (even an accurate one)I would not waste your money on this gear. You will see many times more return dialing your OCW and fine tuning the load than with high dollar reloading gear.

FYI.
The custom ground part of the die is the neck area. The thinking here is to remove the expander completely and to have the die take everything down in one step...It works well, but you have to be able to nail the sizing correctly (same as with a bushing). It adds $10.00 or so to the standard die....So is not too expensive if you only need a couple. That said this is F-class/benchrest stuff and you will NEVER see the accuracy increase in a hunting rifle and you would be far better of spending your money elsewhere...Just telling you what my targets say.

I can statistically "see" accuracy improvement as concentricity gets better in my 40X scoped near 20lbs 6mmbr, but this is a rifle that has shot 0.1" groups and under 1/3MOA at distance. This is not a hunting rifle nor even close to a tactical rifle....Just so we are clear. The most accurate of tactical rifles may benefit from this fine tuning, but even then the differences are so small it is not generally worth the aggravation.

Straightening your ammo creates more problems that it solves. I would not bother.

I hope that answers your questions.
Let me know.

Peace
 
Re: Concentricity woes...

Some interesting discussion. I for one don't measure runout, have never felt the need, that's not to say however that it doesn't have its merits, maybe if I got into benchrest...

To the OP, I think you've been attempting to fine tune an area that in reality gets lost in the overall set up. Two things to consider, firstly its a factory rifle, secondly its primarily a hunting rig. It should be accurate enough for the task in hand (depending on your maximum hunting range) and just as importantly function flawlessly. Crimping is done for function and is a trade off against accuracy.

FL size, trim and load to the best of your ability and spend time behind the rifle - that is the thing that is likely to reap a greater reward to accuracy. When hunting, can you hold 1 MOA off sticks or in an uncomfortable, improvised shooting position?

For a cheap way of producing low run out cases look at a Lee Collet Die used in conjunction with a Redding body die. Both are inexpensive and work well.
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: loaded4deer</div><div class="ubbcode-body">Good discussion. OK, so I called Redding. I explained the info above and their response was ".005 that is very very good." I was taken back and speechless. He explained that Redding's position is that concentricity has little effect on accuracy. Few benchrest people are concerned with concentricity. Hence, Redding does not make a concentricity tool. I explained that I've been chasing this sub-.002" number. We discussed the "S" die and carbide expander. He offered to replace my expander and/or polish the existing expander. Also, he offered to check and polish my die for free. Great customer service. To prove his point, he suggested taking really very concentric rounds and against very non-concentric rounds. He said you will be hard pressed to see a difference. I told him I would do the test before sending anything.

Redding said he thought there might be some concentricity correction once the round enters the chamber. Interesting thought. He did not have any supporting examples.

Redding feels much more accuracy is gained in the area of neck thickness. He suggested I sort brass by neck thickness. Anything over .0015" be set aside. He suggested Norma brass for the 300 WSM. Also, he did not suggest neck turning because the feeling is, if the neck is thin, the body is thin in the same areas and could present split case issues.

I had to share that in time I would be crimping these loads and I got an "oh...".

At the end of our conversation, he asked me to measure the expander ball and it should be .001 to .0015 below .308. I haven't measured it yet. He said it is a possibility the expander was mixed-up during assembly.

I still think I am going to get the Carbide expander (can't hurt) and do the accuracy test he suggested. Redding said the expander helps with reduced friction and it floats. It also fits the "S" die...

X-fan...what is the deal the "custom ground and sized Forster seater"? I have never been able to shot any of my stock hunting rifles (.243, .270, .300) into a 1/4 group. I can manage 3 of 5 into into 1/4, but never 5 of 5 with any consistency. This is probably what Redding is taking about. I appreciate your candor.

Paul
</div></div>

Then why does Redding say this on their site in reference to their Competition seater dies ????

This design, covered by U.S. Patent No. 4,862,567, has beat the concentricity problems inherent in all other seating dies of this type.

Tighter manufacturing tolerances have been made possible due to the details of the patented seating stem system. The bullet guide to seating stem fit is so precise that the seating stem can actually be demonstrated to “float” on a column of air.

The seating stem is precision ground to exactly match bullet diameter. No seating die on the market is built to this level of precision. Alignment and accuracy are enhanced by the cartridge case and bullet being completely supported and aligned in a close fitting, precision ground sleeve before the bullet seating begins.

If Redding thinks that few bench rest shooters are cocerned with concentricity issues then they are out of their minds.
I had dealings with the CEO of Redding and found that he is a person that does not seem to understand his customers at all or even care what the customer thinks .
I think the managment of Redding is now very bad and as a result the quality of support and advice is pure crap.
The products are very good however I reckon that will also change for the worst in time if these idiots keep running the company reputation downwards .
Concentricity is important because if you launch a bullet out of center into the bore the jacket will suddenly be realighned on a new axis and not in it's original swaged axis. The worse this gets the more the bullet can be affected by yaw as the base is no longer square to the central axis of the bulet . A few thousandths here or there would be hard to show any difference but why not make the ammo as straigh as possible. .005 is not that bad for hunting ammo and general shooting but I feel that most of your runout is asociated to your loading technique , case prep and possibly bullet seating technique , the fact that you are using an expander ball type die which pulls case necks out of alighnment does not help at all .
My advice is seperate the sizing jobs. Neck size with a Lee collet die and body size with a Redding body die and that will improve the whole reloading process.
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">

If Redding thinks that few bench rest shooters are cocerned with concentricity issues then they are out of their minds.
I had dealings with the CEO of Redding and found that he is a person that does not seem to understand his customers at all or even care what the customer thinks .

I think the managment of Redding is now very bad and as a result the quality of support and advice is pure crap.
The products are very good however I reckon that will also change for the worst in time if these idiots keep running the company reputation downwards .

Concentricity is important because if you launch a bullet out of center into the bore the jacket will suddenly be realighned on a new axis and not in it's original swaged axis. The worse this gets the more the bullet can be affected by yaw as the base is no longer square to the central axis of the bulet . A few thousandths here or there would be hard to show any difference but why not make the ammo as straigh as possible. .005 is not that bad for hunting ammo and general shooting but I feel that most of your runout is asociated to your loading technique , case prep and possibly bullet seating technique , the fact that you are using an expander ball type die which pulls case necks out of alighnment does not help at all .
My advice is seperate the sizing jobs. Neck size with a Lee collet die and body size with a Redding body die and that will improve the whole reloading process.



</div></div>
Don't know if you know who Bruce Baer is (he builds some of the finest and winningest 60 pound 1000yd benchrest rifles on the planet), but in talking to him he confirmed that below 5 thou runout he had a hard time discerning any accuracy improvement. So while benchresters may want straighter ammo (I do as well) the guns really do not shoot better.
So (IHMO) I would not call Reddings advice on this matter crap. Redding does not seem to imply any loaded round runout specifications that I could find.

While your mileage may vary, I never found the Lee Collet die to be in the same class of straightness or neck tension consistency (I run a force gauge on my arbor press to measure this) as a properly tuned up Redding or Forster setup.

Just my experience
 
Re: Concentricity woes...

+1 x-fan , my lee collet never resulted in better runout then my redding bushing die.

i hear allot of talk about how runout doesn't effect group size... lets see some range results to back that up.

ha , you know whats funny... some of my 750 amax bullets produce around .002 runout , the bullets themselves not loaded into a case. If my bullets themselves have .002 runout... then its not going to be possible for me to acheive less then that... i think.
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: X-fan</div><div class="ubbcode-body">Don't know if you know who Bruce Baer is (he build some of the finest and winningest 60 pound 1000yd benchrest rifles on the planet), but in talking to him he confirmed that below 5 thou runout he had a hard time discerning any accuracy improvement.</div></div>

I can confirm that for my rifles (tactical not benchrest) anything less than 0.003 shows no improvement, and 0.004 shows almost immesurable degredation in accuracy.
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MALLARD</div><div class="ubbcode-body">+1 x-fan , my lee collet never resulted in better runout then my redding bushing die.

i hear allot of talk about how runout doesn't effect group size... lets see some range results to back that up.

ha , you know whats funny... some of my 750 amax bullets produce around .002 runout , the bullets themselves not loaded into a case. If my bullets themselves have .002 runout... then its not going to be possible for me to acheive less then that... i think. </div></div>

Dude!
Thanks!
You just saved me so much grief trying to sort out a runout problem!
It never occurred to me the bullets would be out!
I just spun 50-750Amax put it on a spread sheet and got an average of 0.00137! The biggest was near 0.0038!

Worse yet was is some custom turned 800 grainers both not only spun as much as 0.004 they have a 0.001 wobble in the middle! Funny thing is I just shot a 7.5" 5 shot 1k group with them!!

I am about to throw away my fking dial indicator!
smile.gif

Never buy a micron capable dial indicator for reloading btw...You will see things you just don't want (or need) to know.
 
Re: Concentricity woes...

Reality strikes! Any hunter knows is it VERY hard to shoot sub 1 MOA as you describe. I'm not sure I could with any consistency. The environment plays a role as well. Fortunately, the killzone on a deer is say 6-8 MOA at 100 yds. Since I love reloading, I have no problem taking time and $$ to work a hunting rifle load into the sub-MOA zone. It's fun as hell. I want the gun to shoot as best as is can, then the rest is on me. At the range, I shoot off a sand bag front, nothing but shoulder in rear...

Good points.
 
Re: Concentricity woes...

I was thinking the same thing. I can't speak for Redding, but I am a business man. As a business man I would guess it is a response to market demand. Serious benchmark shooters demand top performance and words like "match" and "minimum tolerance" reach this market.

FYI, AJ was the guy at Redding I talked to.

I think I worked myself in to a Concentricity frenzy. Once you see what .005" RO look like in the tool, you have nightmares of the lost buck...

I'm going to start with the carbide expander. If that doesn't work I will separate the process into two stages.

Thanks!
 
Re: Concentricity woes...

My buddy is going to use his Hornady Concentricity tool to <span style="font-style: italic">increase</span> the RO on his pet load.

More data to come...
 
Re: Concentricity woes...

Mallard / X-fan -

Brilliant! All of this dialog makes sense. The part that confused the hell out of me is measuring the RO of varying parts of the case and bullet. Sometimes the bullet is straighter than the neck. I'm telling myself right now to GET OVER IT! lol

Thank you guys!!!
 
Re: Concentricity woes...

Loaded4deer,

In your earlier post you indicated that you corrected RO and got an ES of 4fps. Was this done with the Hornady contenctricity tool? If so, why are you going through the trouble of buying additional dies if you can get results like that?

lastly, is this improvement consistent whenever you employ the hornady concentricity tool?

Btw, what about FL sizing using any old sizing die, then applying the lee collet neck sizing die afterwards?

Thanks again. Sorry for the thread Hijack.
 
Re: Concentricity woes...

Tx_Flyboy -

I checked every round for RO with the Hornady Tool and corrected to sub .002" (if possible). The RO straight from the die was anywhere from .001" to .006". One out of ten rounds needed correcting to hit this .002" number I had in my head as "PASS", which is really where I went wrong. The reality is I never shot the gun without checking and correcting RO. My next trip to the range I will test without using the tool and see if I can repeat my prior best load.

I do not believe the RO and ES are connected. The ES was a result of the finding the node and bullet, powder, OAL, combination etc...

The Hornady tool is a pain in the ass. After using it for a while, you learn it's limitations and how to get the best results. Based on the advice I'm getting, loads that are over .005" will be fouling shots. Anything under will be for accuracy shooting.

RE dies - overworked brass would be a concern.

I learned a lot from the dialog here. I will get the Carbide button tomorrow, use it and yet still de-emphasize the importance of RO and continue load development.

My buddy did his testing over the weekend and I hope HE will post his results soon. If not, I will. To cut to the chase, he saw very little difference with .005" RO out to 200yds. He was still shooting about .6 MOA with ammo at .005" RO.
 
Re: Concentricity woes...

loaded4deer.

Something i don't think was addressed yet is the bullet seating process (not the die choice). I have always used Redding Competition dies. My bullet seating process was to put the powdered brass case in the shell holder, hold the bullet to the case mouth, and run the handle of the press all the way up until the bullet was seated to its final OAL, one stroke, one loaded round.

When i started measuring RO a few years later i noticed that my rounds would have anywhere from .005" to .007" of RO. I got on benchrestcentral.com and asked them what was causing this. They suggested i do two things. One, run the handle of the press up with a brass case in the shell holder and set the lockring of your die with the case in it. This is to align and eliminated RO of the die itself by aligning the die with the brass body. Two, start the bullet only about 1/3 of the way seated, then rotate it in the shell holder a 1/4 turn and seat it a little more, rotate it another turn and seat it a little more, and then all the way to its final OAL. Ever since i switched to this my rounds have produced .002" RO or less. I use Norma WSM brass.

I use their FL sizer with a bushing, no expander ball.
 
Re: Concentricity woes...

OK, did some testing over the weekend and have some data that may be of use. 5 round groups were shot through a stock R700 .308 SPS-T @ the 200 yd line.

1st.) A control group using factory HSM 168gr match loads. This produced a .624 MOA group. For factory target ammo, I prefer HSM over FGMM.

2nd.) Used the Hornady tool to create .005 Run-out (RO) to my hand-loads (168gr SMK over 43.5gr Varget in a Federal case and WLP primers). Group was .670 MOA.

3rd.) Group was interesting. Used the Hornady tool again to create .010 RO and then pressed it back to .001-.002. It was pretty tough tweaking the loaded round that far but I was looking to see what affect all of this monkeying around with the neck tension would do. After the 3rd round I noticed the OAL was noticeably shorter than the "non-tweaked" rounds were. Upon inspection, the case neck loosened up so much the bullet was now barely finger tight in the case. I finished out the 5 rounds and then used my fingers to pull the bullet out a bit then used my OAL gauge to set to my normal OAL. I chambered these 1 round at a time and was careful to keep as consistent OAL as possible when shooting. This produced a .564 MOA 5 round group with 1 flier. If just using a 4 rd group, it measured .325 MOA in a vertical string.

4th.) Shot my normal hand-loads that produced a .493 MOA group. These rounds were right off my Dillon 550. All of them measured below .002 out of round and no tweaking from the Hornady tool.

All shots were chrono'd with a Beta Chrony and hand-loads were on average 2500fps and the HSM was an average 2532fps.

Thoughts?

@ Mule hunter - I used to do the "seat part way then rotate and seat some more" but found it didn't change anything on my RO. I actually have slightly better RO by just pressing all the way up in one smooth motion.
 
Re: Concentricity woes...

CSAR,

Did you measure ES of the individual groups with the chrono? If so, please post them.

Lastly, with regard to the 3rd group that exhibited loose bullets, is this always the case with the hornady concentricity gage?

It seems as though your dies exhibit very little runout...what dies are you using? If you've posted this before, i missed it.

Thanks again.
 
Re: Concentricity woes...

I'm sure the hardcore guys are going to hate this, but I went from a Sinclair concentricity gauge to the Hornady, which some consider a joke, and I'm fine with it. And I think folks forget that concentricity begins with a decent press and dies.
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tx_Flyboy</div><div class="ubbcode-body">CSAR,

Did you measure ES of the individual groups with the chrono? If so, please post them.

Lastly, with regard to the 3rd group that exhibited loose bullets, is this always the case with the hornady concentricity gage?

It seems as though your dies exhibit very little runout...what dies are you using? If you've posted this before, i missed it.

Thanks again. </div></div>

Tx,
I don't put a ton of weight into the ES/SD with numbers from the Chrony. Seems they're not always 100% reliable. I'm guessing the short separation distance between sensors and how much the cloud cover/sunshine can affect things.... plus it's a cheap chronograph.

ED / SD
1.) 53 / 26
2.) 40 / 16
3.) 49 / 21
4.) 38 / 15

The extreme amount of tweaking I did to the loaded rounds (#3 group) is way more than anyone should need to do (or want to do). I've corrected rounds before but never needed to do that much work so I've never seen this type of thing happen before. After seeing it, I did go back and check my normal hand-loads and there wasn't any bullet movement.

I'm using basic Dillon .308 dies. De-cap and full length size on station one. Throw and trickle up powder (not using press), Prime with a Lee thumb press, then seat bullet on station 3. Basically using it like a single stage press for the .308
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CSAR</div><div class="ubbcode-body">2nd.) Used the Hornady tool to create .005 Run-out (RO) to my hand-loads </div></div>
what do you mean "to create .005" ? how exactly are you doing that ?

intersting test. You shot groups at 200y threw your chrono ? that itself is pretty impressive. I find it a PITA to setup a target and chrono like that , especially at 200y. nailed my chrono a few times.
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MALLARD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CSAR</div><div class="ubbcode-body">2nd.) Used the Hornady tool to create .005 Run-out (RO) to my hand-loads </div></div>
what do you mean "to create .005" ? how exactly are you doing that ?

intersting test. You shot groups at 200y threw your chrono ? that itself is pretty impressive. I find it a PITA to setup a target and chrono like that , especially at 200y. nailed my chrono a few times. </div></div>

Mallard,
The Hornady tool has a thumbscrew that you use to push against bullet to either increase or decrease the RO. Chrono was 15ft from my muzzle so not really a big deal shooting through it to the 200 yd butts.
 
Re: Concentricity woes...

After pressing the Hornady tool to create more runout the loaded rounds are (as mentioned) somewhat deformed..Hence why I do not recommend the tool to begin with.
I am surprised and how consistent the results were, but I don't think one could draw any conclusions here.
 
Re: Concentricity woes...

With factory stock SAAMI chamber specs, concentricity tends to be a lot less critical than it would be for a custom, tight-neck chamber.

I'd be more concerned if there was some evidence that llnked the RO to actual, on the target accuracy issues.

I can appreciate the concern regarding making perfect ammo. But I also think its iomportant to have a clear and indisputable actual problem before getting warked up over fixing things.

There can be a considerable difference between 'imperfect' and 'broken'. It's only 'fixed' if you can see a significant difference on the target.

If you can't, maybe the issue isn't about how to fix the problem, but whether the imperfection actually equates to a real problem in the first place. You can't fix what isn't actually broken, no matter what lengths you go to in improving concentricity.

Greg
 
Re: Concentricity woes...

I was running a process like this for my 308 and had runout variability. I spoke with the guys at Redding and we sorted it by making sure the inside chamfer was substantial. You live and learn. Without measuring step by step and input from Redding I would never have got there.
hmp.gif
 
Re: Concentricity woes...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">With factory stock SAAMI chamber specs, concentricity tends to be a lot less critical than it would be for a custom, tight-neck chamber.

I'd be more concerned if there was some evidence that llnked the RO to actual, on the target accuracy issues.

I can appreciate the concern regarding making perfect ammo. But I also think its iomportant to have a clear and indisputable actual problem before getting warked up over fixing things.

There can be a considerable difference between 'imperfect' and 'broken'. It's only 'fixed' if you can see a significant difference on the target.

If you can't, maybe the issue isn't about how to fix the problem, but whether the imperfection actually equates to a real problem in the first place. You can't fix what isn't actually broken, no matter what lengths you go to in improving concentricity.

Greg </div></div>

Greg,

It has been a few years, but in my discussions with Bruce Baer (had him build me a rifle) he claimed after extensive testing he could not see any increase in accuracy below 4 thou....And that number may have been 5 thou...I can't positively recall.

Apparently they went to great pains to make quality ammunition that was from dead straight (0.000 to 10 thou) in one thou increments. The results were published in Precision Shooting and I ended up getting a copy, but can no longer locate it. The testing was done in ultra precise 60 plus pound unlimited heavy bench rifles (see the link below for the rifles).
Heavy Bench