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Concentricity gauges, let's hear it if bench loaders and accuracy guys....

Discussion in 'Handloading and Reloading' started by RussellC, Sep 11, 2017.

  1. RussellC

    RussellC Member

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    Opps, the title should be "hear it", not "hear if"..........

    In the ever continuing quest for more accuracy, I have decided to drive myself nuts with one of these gizmos. I have read bench loaders recommendations, watched you tubes, searched and read articles here, accurate shooters, and various other sources trying to come to a conclusion on which one to buy.

    Like most things, opinions on various units are all over the place from many differing sources. I have looked at Redding, Hornady, Sinclair as well as a few others.

    I load my rifle ammo with the Redding Competition Micrometer neck bushing die, the Redding Competition Micrometer seating die along with the Redding Competition body die and Redding Competition Shell holders to adjust shoulder.

    Please advise me, Ye old bench rest shooters, which concentricity gauge do I need?

    Thanks,

    Russellc
     
  2. 444

    444 Member

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    I am not the guy to ask, but this subject has interested me lately. A buddy of mine loaned me a Sinclair.
    So, I have been watching YouTube videos and there are several out there that are made by small shops and not the major reloading manufacturers and they look to me like they would be easier to use than this Sinclair.

    So, I am basically tagging this thread to hear the answers.
    I was actually going to start a thread just like this over the last couple days and never got around to it.

    On a related subject, I would be interested in hearing what kind of concentricity other people consider to be adequate and realistic. I am not a formal benchrest shooter. I am a guy shooting "regular" guns who loves accuracy. I don't hunt, or compete; but I shoot probably four days a week at paper and steel and am trying to up my game in the reloading department more so than the gun department. I would also like to hear what you can do to improve concentricity: there are all kinds of videos about the various gauges as well as how they work: but almost nothing about how you can get better concentricity.
     
  3. RussellC

    RussellC Member

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    Well, sounds like we are in a similar boat. As far as gaining better concentricity, what I have gleaned thus far is to get the best dies you can. This led to a similar tail chasing event, but I settled on Redding Comp. Micro. dies. I may replace the neck dies with three or so Sinclair units honed to my neck specifications, we will see.

    I am starting to read threads about techniques on use of these dies, here, accurate shooter, long range only and a few others. Another thing that led me to the Redding Comp dies is their tech dept., which I hear helps with lots of info concerning the use of their products like these.

    I decided to start this learning curve with a Savage 12FV in .223. This will be the least expensive option, plus I shoot AR15 rifles as well. Once the curve is learned, I will buy gun and dies for .308 or 6.5 CM.

    Here we go, I will learn or go screaming into the night, having spent a lot of money on stuff.

    Russellc
     
  4. 444

    444 Member

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    I just ordered a 12FV in 308. I also have a Savage in 6.5 Creedmoor.

    Ironically, the thing I have been trying all this stuff on is a Ruger American Rifle in .300 AAC Blackout. Why ? Because it didn't shoot very well and I was trying to figure out how to make it shoot well. And I have come leaps and bounds over the last two months of playing around with it. I started weighing my cases, then I just cut to the chase and bought Lapua cases. I am sizing them in an LE Wilson hand die on an arbor press. I have cut my group size more than in half by playing with loading techniques as well as trying all kinds of bullets/powders/primers.......................

    The 6.5 Creed shoots pretty damn good as is, not that it couldn't be better. But, just like you, I am going to figure all this stuff out and then apply it to the 6.5 and the .308.
     
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  5. edwardware

    edwardware Member

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    As I've said. . .

    I wondered this exact wonder this past year, so I did an experiment!

    I built a concentricity gauge and characterized a couple batches of ammo for my R700 SPS Tac (.223 bull barrel), benched and bagged. In a batch of 50 rounds I separated into 3 tranches, A: 0-3, B: 3-10, and C: 10-30; units are 0.01mm of runout, measured at the leading edge of the bullet's major diameter vs the case shoulder and case base.

    I found. . . no difference whatsoever in group size! I shot the groups across 3 range trips, A, B, C, B, A then C, B, A, B, C, etc. I was a rigorous as possible within the constraint of 50 rounds (and I design test plans for a living).

    I'm certain that concentricity effects accuracy, but I have proven to myself that with my equipment and my average group size of ~1 MOA, it's not measurable. After I've shrunk my groups down to ~0.75, I"ll rerun the experiment and see if I can measure the effect.

    If you don't yet have a gauge, save your money and do your own experiment; take a batch of 50 identical rounds and separate them visually by rolling across a flat surface and looking for wobble. Shoot your 10 best and 10 worst, and see if you can measure a difference.

    Edit: I also found that, just as Redding will tell you, the vast majority of runout is caused by brass (neck thickness and modulus variation) and the sizing die. The seating die doesn't seem to matter at all. This discovery cost me a $100 Redding seating die; it's wonderfully adjustable, precise, and repeatable, but the ammo it produces is no more concentric than what I make with my roughly-finished Lee seater.
     
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  6. RussellC

    RussellC Member

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    What distance are you shooting at? Much of the reading I am doing regarding benchrest shooters think it makes a difference, always seeking less variation between rounds. I dont doubt what you are saying, but I have a feeling it will make more difference the further the distance? Hopefully Walkalong, and others who have done significant bench rest shooting will weigh in on this...

    Russellc
     
  7. RussellC

    RussellC Member

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    We are on a similar journey. The 300BO is of course based on the inexpensive and plentiful .223 case. Cheap learning I figure. Even the .223 Lapua is fairly reasonable. I am hearing good things about the Starline .223 brass, its cheaper than the Lapua.

    I havent weighed cases, but I did buy one of those little primer hole plug that allows you to weigh the water required to fill the particular case.

    Russellc
     
  8. jmorris

    jmorris Member

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    I went through this awhile back and built two different styles.

    This is the first one, 4 ball bearings, 3 hunks of aluminum, 1/4" dowel pin, 1/4" stainless rod threaded on one end and two socket head cap screws. It's very versatile as I can measure from .17 hornet to 50 BMG, just the case alone (inside or out) or a completed round. I can also move the front support to different locations so it's easy to go off the neck, shoulder or anyother area on the case.

    image.jpeg
    Shortly after that I added another post that holds a disk of aluminum and used an o-ring for a "tire", makes it easier to use.
    image.jpeg

    Then awhile after that added another accessory that slides over the dowel and extends back to the indicator tip, where the two bearings contact easy other. Allows for a very fast and non destructive way to measure case wall thickness.

    image.jpeg

    Then I built this one that is super easy to use but only works on loaded rounds and not as many as the first one.
    image.jpeg

    Results with ammunition with differing runout have other variables. If the rifle won't shoot well with perfect ammunition, "bad" ammunition doesn't seem to hurt it as much. Also when testing ammunition of differing amounts of run out, it's worth measuring runout, then chamber and remove the round and remeasure.

    With more than one combination I tested, runout went away after being chambered. If that is the case in the observation above, it's not that runout doesn't matter, rather it was "fixed" when chambered.

    I don't think one "needs" a runout gauge but one can answer questions that are difficult to answer without one.

    I also think it's worth measuring runout of a fired case, then one that is sized with the decapping pin/expander removed and then one with the decapper/pin installed. If you can't get good results at this point, they don't tend to get better down the line.
     
    Last edited: Sep 12, 2017
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  9. Nature Boy

    Nature Boy Member

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    Here's what I observed when I went down this rabbit hole last year (BTW, I'm still down here with the rabbits). TIR noted on 3 each 10 shot groups using 168 Berger VLDs in my FN SPR .308

    19198121-FBA8-4748-9D26-CA75DB0C303F.jpg

    It's enough of a difference for me to keep measuring and correcting it. I use the Hornady tool to do that

    530322E3-6CEA-4692-8068-CF5A41CB36BD.jpg

    Please, someone show me that this is a waste of time. I'd love to quit doing it as it's a tedious process to measure and correct every round
     
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  10. Sunray

    Sunray Member

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    None if you aren't shooting bench rest matches out of a bench rest rifle. No point to any of that kind of stuff for an entry level hunting rifle like an SPS. Barrels aren't up to bench rest accuracy. Most of those assorted gauges are primarily about separating you from your money.
     
  11. Walkalong

    Walkalong Moderator

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    Not entirely correct, many of our member have rifles and abilities than can take advantage of it. That said, yea, for the average hunting rifle and loads for 100 yard shots it would not be needed and the rifle shooter may not be able to take advantage of it.

    But the OP is asking for friendly feedback, not a blanket "your wasting your time" statement. ;)

    Straight ammo never hurts. :)
     
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  12. Nature Boy

    Nature Boy Member

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    True. We're not talking about affecting accuracy that would concern someone who's sticking 3 rounds in a paper plate at 50 paces and calling it good
     
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  13. RussellC

    RussellC Member

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    I made NO mention of hunting rifles, I do my hunting in the Supermarket. This is for punching paper, and accuracy is why I do this. Looks like to me its worth the trouble for my purposes. I don't need anyone to tell me I am wasting
    my time, that could be said of anything someone else does not see as a priority. I build/modify guns for the sake of accuracy, not shooting for hunting purposes, which I see as a waste of time. Many love to hunt, and I am sure
    it isn't a waste of their time.

    I used to sell guns, deer tags and all that stuff for a retailer in the 80's. Guys came in, bought rifles, scopes, bullets, dear tags, tents and all that for a deer hunt that half the time they didnt get one. For the same money, I could buy a side of prime beef, and have a professional butcher cut and package it in 5 star restaurant cuts. Did those guys think they were wasting their time? Certainly not, they were doing what they enjoyed and were ready to go again next year.

    Some folks think the world started the day they were born, and to disagree with them is foolish. Sorry, that's not how it works, we all have different priorities, hobbies, enjoyments as well as dislikes. Look at what the other guy is doing, you may find something that surprises you. Be a sour lemon, and you get the sort of thing that draws.

    Thanks guys, Walkalong, Nature Boy, Jmorris, for your inputs. I know edwardware and 444 appreciate the input as well.

    Thanks all,

    Russellc
     
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  14. Offfhand

    Offfhand Member

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    Mr. Walkalong is making a valid point, which I second. A runout gauge, when understood and used properly (Another matter) can supply valuable feedback on one's loading equipment and loading techniques. Attached is a photo of a runout measuring instrument made by Ferris Pindell, a master machinist and accuracy expert who, among other accomplishments, was co-creator of the PPC cartridges. Note that the indicator is positioned at the tip pf the bullet. Pindell1.JPG
     
    Last edited: Sep 13, 2017
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  15. RussellC

    RussellC Member

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    Very, very nice. Thanks for that.

    Russellc
     
  16. Varminterror

    Varminterror Member

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    I have the Sinclair and the Hornady - buying the Hornady second for the ability to correct run out - which I've largely discovered is not much more than marketing. In tests similar to Nature Boy's, I have noted better performance from lower run out, but only if the ammo left the press with low run out, and "correcting" it with the Hornady tool hasn't proven to close that gap for me.

    There are FAR more critical contributions you can make to improve your precision than adding a concentricity gauge, however.
     
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  17. murf

    murf Member

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    i use an rcbs concentricity gauge. i'll take anything less than .003" runout. anything over that i use for things other than small groups. i also turn necks and uniform primer pockets.

    i'm an old varmint shooter and have been chasing small groups for 50 years.

    luck,

    murf
     
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  18. murf

    murf Member

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    not me!

    murf
     
  19. 1066

    1066 Member

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    I think striving for straight ammo can never be bad - just another step in making the best ammo you can (if that is your aim). A modern press and dies, along with good brass and bullets will mostly produce good ammo out of the box. If, however, you want "better" you need to pay attention to the details. Many steps in the case prep procedure are difficult to quantify, primer pocket uniforming, flash hole deburring, etc. etc. but when you have that round in your hand on the 1000yd line, you know if any thing goes wrong, it's not the ammo.

    Here's a couple of my homemade concentricity gauges.
    pEosxHr.jpg


    [​IMG]
     
  20. Blue68f100

    Blue68f100 Member

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    Does any of the gauges check to see if the base is square? All of the ones I've seen just ride against a stop. I would think a more accurate setup would hold the cartridge base square. Then you see the whole picture. But if your shooting a gun that has been blueprinted you are square. For the common folks this is where probably the most error is out. If you don't start off square, everything is off.
     
  21. jmorris

    jmorris Member

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    ^ Top shelf craftsmanship on both of those.

    And that is the reason I made the ones I have. To get real numbers when changing the various numbers vs just thinking something is better.

    Once I had a way to measure finished product with precision I had a better understanding of what makes things better or worse.

    For example I now know what dies are used makes a larger difference than the type of press I use.

    So I can put good dies in a progressive and turn out more precise ammunition than I could with a lesser set of dies in a single stage. The huge gain in production cuts reloading time much more than it took me to build the tools and test things. So for me at least, it was and investment of time I have gained back many times over.
     
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  22. jmorris

    jmorris Member

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    If the base is not square the case will move back and forth because they are tapered and only contact the rear post at one point. Any back and forth movement on a tapers part will register on the indicator.
     
  23. Nature Boy

    Nature Boy Member

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    The Hornady tool locates off the case rim and bullet tip using a taper on both ends.

    Even though I sort of proved to myself that doing this is worth it if your goal is chasing perfection, here's why I think it's a bit of a fools errand.

    I'm correcting to achieve a total indicated run out of 0.001 or less. This is a non linear measurement meaning that we're talking 0.0005 per side.

    Seriously.

    Perhaps one less cup of coffee might make more difference down range.

    That said, I'm still doing it.
     
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  24. 1066

    1066 Member

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    Personally I never bother to correct them if they're wonky, I mark them and use them for fouling shots etc.. I use the gauge to find out where the error is creeping in and fix that, once everything is set up well then the gauge is rarely needed.

    I would be concerned that pushing a crooked round straight would vary the neck tension.
     
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  25. Walkalong

    Walkalong Moderator

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    Yep.
     

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