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Thread: Runout - how much is too much?

  1. #1
    Member bgreen's Avatar
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    Thumbs down Runout - how much is too much?

    At what point do you start pulling bullets?

    I've just reloaded a few 165 grain Barnes TSXBT that have between .001 and .006" runout. I've already tested these loads for pressure and am headed to the range on Sunday to run them over the chrony and test for accuracy. Most are .003 to .005" runout, what would you do? Should I pull the bullets and start over?

    I am building this load for caribou, sheep, black bear, and the occasional long shot at a wolf or coyote. I'd like to shoot 3-4" groups at 300 yards.
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    A long time ago I read an article concering your question and all the details escape my memory but I seem to recall the author stating you should stay under.003. If the rounds were further out of alignment than this he had good luck with indexing the rounds so that the same point of the extreme runout was postioned in the chamber.
    But to be honest this is all here say. I suggest you simply take them out and segerate them into different "lots" and see if any difference can be detected in your group sizes.
    Your results may vary but the most important aspect of my groups are me, the shooter.
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  3. #3

    Default Runout

    Odds are your problem is from case necks that are misalligned or not uniform.And pulling the bullets won't change anything.

    Runout is a function of what dies you use to load/reload...how uniform your brass is to start with...what steps you apply to true necks...whether those steps are applicable to hunting situations...and how meticulous your reloading techniques are.Many seating dies are not threaded perfectly concentric with the press ram.Getting the expander ball perfectly centered in the case neck is fundamental.

    Depending on the firearm, just cycling a round from the magazine into the chamber can screw up (induce runout) on the most closely toleranced ammo.

    Further, very few casual shooters and hunting rigs can produce MOA at 300 yards.Sorry, but that is reality.

    Shoot your stuff at 300 and see what the group size is.Decide if it is "minute of bou or sheep". And quit worrying.

  4. #4

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    Quite a spread in run-out, so long term I'd think about how to minimize it. But in the short term, it sounds like a great opportunity to experiment. How about sorting your loads by degree of runout, then firing groups? If you see a difference, then you've established the standard you need to strive for in reloading. If your rifle doesn't respond, there's no sense in putting the effort and bux into refining your setup.

    Unless loads are unsafe, I almost never resort to pulling bullets. We almost never get enough practice offhand shooting, so if nothing else I'll fire up the ammo in shooting practice rather than going through the tedium of pulling (and probably damaging) bullets for reloading.

  5. #5

    Question Runout?

    Could you explain "runout"? Sorry to be a ditzel, but this is a term I'm not familiar with...must be that vaccum I've been living in. Thanks, ciao.
    If you like getting kicked by a mule...then you'll "love" shooting my .458.

  6. #6

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    It refers to the alignment of the bullet to the case and the bore. Bullets can actually be minutely "crooked" in the case to the extent that accuracy is degraded while still not being crooked enough for the eye to see. Tools called runout gauges are standard for measuring it, but you can spot large amounts of runout simply by slowly rolling a loaded round on a smooth flat surface and watching to see if the bullet "wiggles" as it rotates. Like I said, you can see big runout this way, but probably not the small stuff. It's a useless issue for most rifles and most hunters simply because the difference wont be apparent in their shooting, but it can be a big deal for high precision shooting.

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    Member Big Al's Avatar
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    7STW, nailed it. I could not think of anything to add, unless you might want to try that run out trick on factory loads also.

    You might want to remember that thickness differences that show at the neck are indications that the problem runs the length of the case. Longer cases are more prone to this than short cases.
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    I don't think 3-5 thou is excessive. I find it to be about average. I did some experimenting a few years ago and separated out the <.002 out from the >.005. For me these are also the extreme ends of the spectrum and you only get a couple of each of these out of 20 rounds so my samples were limited. I think I shot 2 groups of three with each runout range. For whatever reason both >.005s shot a little better. I stopped regular measuring after that.

    I do find it useful for measuring a new gun to check the bore and also to check a new set of dies. Check the neck runout on a once fired case before putting it in a die to check the bore, run the case through the sizing die without the expander ball to check the die. My guess is your runout is coming from the expander ball. When I size a case without the expander the runout is nil. Same case after pulling the expander through is typically .002-.004.

    I was able to measurably decrease my initial runouts by being more careful with lubricating the inside the neck. And now I also polish the expander ball to a mirror finish on a buffing wheel, it only takes a few seconds. Like I said above, most of mine are 2-4 , but I really doubt your 3-5 will make any difference at the range. If I was regularly over 5 I would be doing some troubleshooting.

    Check one that makes that squeaking noise when you pull the expander through. Betchya you'll have a .007 or higher.

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    Member bgreen's Avatar
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    Thank you for the replies fellas, much appreciated.

    I started thinking about the situation today and haven't been able to tie it down to anything yet, but I think it may have something to do with new unfired brass and the fact that I'm checking run-out on a standard V-Block that bears on the entire body length of the case. I need to build something that only bears on the case at the ends of the case to prevent any rocking that may be occurring with my current setup. I also did not full length re-size this brass as it was new and already much shorter than my chamber.

    I used spray lube this time too, so maybe that has something to do with the run out. After I fire some of these loads I will do some experimenting with other lubes and using a spacer to load the sizing and seating dies when I set them.

    I also question my neck trimmer. I know it has some runout and might possibly be distorting my brass.
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  10. #10
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    Recently when loading up some dummy rounds for my 458 Lott I discovered the cases would chamber easy when empty. But once I seated a bullet using my new Hornady Dimension dies the seating die would actually cause the case to bend preventing them from chambering. The dies went back and Hornady confirmed they were the culprit.
    Just curious, are you using Hornady dies?
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  11. #11

    Default Expander ball

    A tried and true approach to truing the expander ball shank...and ball...goes like this:

    1.First, case necks must be inside lubed...and afterwards cleaned.I've used a cleaning patch with cleaner degreaser on a Q tip for years...works great to get the gunk out of case necks.

    2.With a once fired, inside neck lubed case...doesn't matter if it is a neck sizer or FL...loosen the expander shank so that it won't arbitrarily center out of line.Who knows where these are preset at the factory?

    Next, run rhe expander ball gently down through the neck...just to the point where you feel no tension or resistance.At that point, start to raise the ram handle until the ball enters the case neck.

    Maintaining just enough "up pressure" on the ram to keep the ball in place,retighten the shank and locking nut(s) on the die to secure this setting.

    This allows the closest vertical alignment your dies, shellholder and press will permit. It will help to ensure there is no additional runout from the neck expansion operation.

    Of course, the crappy brass issue can't be solved this way.Only outside turning or inside reaming will work there.Both a PITA and not needed or even practical for hunting purposes.

    Still, the step outlined above can help to limit runout and is easy to do.

  12. #12

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    Hey bgreen. I'll repeat my recommendation to experiment with the shells you already have loaded. Sort them by degree of runout, then shoot them. While precision guns respond well to RO management, lots and lots of hunting guns barely respond, if at all. It's a good idea to keep tabs on it and use techniques to minimize it, but there's no sense buying extra reloading gear for a gun that's not going to respond to the treatment.

    It all boils down to your accuracy needs or expectations for a particular arm. While I enjoy wringing the best possible groups out of any particular rifle, the difference between 1" and 1 1/4" groups in a hunting rifle is not worth the extra bother and expense in most field uses.

  13. #13

    Question Good or better brass

    I will pose this question and know everyone has there favorites but when it comes to different brands of brass is there one more true than others.

    I am to the point where I need more 300wsm brass, have been loading federal and would like to keep consistent. Anyone do any research here.

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    Default Concentricity

    Bgreen,

    Clearly you've got a good grasp of the mechanics of concentricity. Ironically I started messing with it the same way you have, because that is what I had, a 3" Starrett precision V block. And quickly like you I realized I was measuring the surface imperfections on the outside of the case. Suggestion, since you already got the indicator just buy one of the setups. I have the Sinclair. I rarely use it but when I want it I am glad I have it. Not likely to fix any serious problems but good to be able to eliminate what the problem is not.

    You're right about the case trimmer. You need to start with a piece of fire formed case.

    1. Measure the fire formed case neck to see if any runout is coming from the gun, probably not but good to know for sure.

    2. Remove the expander ball/pin and resize the case. Neck or full length doesn't matter, whatever you use normally. Measure again to check accuracy of the die. Again good to know for sure.

    3. Follow your normal neck lube technique and resize again with the ball. Check what runout was added. My guess is this is where it will showup. Try a few cases for consistancy.

    NOTE: I prefer to just bottom out (light finger tight) the expander/pin locknut on top of the die. This holds it in position to avoid breaking the pin by missing the primer hole but it is quite compliant to self-center in the neck thereby not affecting the neck position. I don't see any advantage to tightening this, just allow it to self center.

    4. Seat a bullet and measure on 2 places along the neck and at least once on the bullet. This will check for problems with bullet seating and neck thickness issues. If the concentricity is worse as you move farther down the neck and bullet then the bullet is in crooked. You can compensate for this a little by turning the case 90 degrees halfway through the bullet seating. If the number is consistant along the axis then the bullet is simply offset probably due to variations in neck wall thickness. I would ignore it for hunting purposes but you could buy a different batch of brass, better brass (norma/lapua), eventually measure it with a neck thickness micrometer (I have one of them too), or turn down the necks (a different topic and may be excessive for many hunters).

    I have fun messing with these things. I always enjoy taking hunting and shooting to a deeper level.

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