neck runout with redding bushing dies???

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by JustC, Mar 9, 2003.

  1. JustC

    JustC Well-Known Member

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    My redding bushing (neck) die is giving me .002" runout on my cases. They come out of my chamber at NO MORE than .001". I polished the expander ball slightly, and it fixed some of the cases, but amny still come out at .002".. Whats going on here? Do I need to remove the expander ball all together? Loosen the decapping rod lock nut, and then retighten after the downstroke of the press to center the expander ball?

    Thanks for any help.
     
  2. Guest

    Guest Guest

    If you are using a bushing die--get rid of the expander ball. You can check your runout without the ball to see if its the problem--I'll bet it is...
     

  3. Guest

    Guest Guest

    CJ is right on, get rid of the expander ball, do not look back.
     
  4. JustC

    JustC Well-Known Member

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    Thank you gentlemen. I am in the process of calling reding to get the replacement collar for the ball. It was not with the dies when I got the rifle, I figure the guy just misplaced it.
     
  5. Tim Behle

    Tim Behle Well-Known Member

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    If you didn't get the expander with your dies, it's because they don't come with an expander. At least mine didn't.

    That's why I switched to the Redding neck bushing die, no Expander ball to mess things up.
     
  6. CatShooter

    CatShooter Well-Known Member

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    First off... the nice thing about the bushing dies is that you DON'T use an expander ball. Just use the bushing that gives you the finished neck size you need.

    But to address the real problem. If the necks are not uniform in thckness all around, you will get sized necks that are off center.

    Supose that the necks are 0.015 on one side, and 0.010 on the other.

    If fired in a PERFECT chamber, and the outside of the case has 0.0000" runout, the neck center axis (of the empty space) will have an error of 0.0025" compared to the outer surface.

    So you are starting off with a problem... now when you size it, the thinner side will size more than the thicker size, so you can wind up with anything in the way of error.

    But... a finished runout of 0.002" should not cause any lose of sleep, unless you are anal compulsive.

    CatShooter
     
  7. BountyHunter

    BountyHunter Writers Guild

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    JustC

    What is your runout on the loaded rounds? Do not waste time on case runout after they have been fireformed if your chamber is straight. Any runout is coming in sizing and seating bullets. Loaded round runout is most important!

    where and how are you measuring?

    Turned necks?

    I have cases with .003-.004 and when loaded, right on, and occasional the other way around. With a custom neck bushing die on my 6.5/06 I am averaging .001 or less, maybe 3 out of 50 rds, running out to .002 and 1 out of 50 that hits .003. and never same case each time, tried marking them. Those over .001 go into a sighter box. Last 2-3 sighters are always match rounds (just for comfort sake).

    My 300wsm, rarely ever has a loaded round over .001.

    Now all of these are neck turned, which is absolutely essential to control runout. Not just once, but again after I first fire them. This second turning really helped stop any runout I was having. Helps clean up any grooves or donut. If not a tight neck chamber, turn just enough to hit the high spots on the neck and adjust your bushing size accordingly.

    Stay with good custom bullets, and work up good loads. First matches, forget doping wind, just follow sighters, concentrate on good position, same hold and smooth trigger. Too much to think about will result in sensory overload and you will walk off the line not knowing what you did.

    Good luck

    BH

    Good luck.
     
  8. JustC

    JustC Well-Known Member

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    Bounty Hunter, I measure after neck sizing on a case master guage. The loaded rounds are the same. I beleieve that it is in some way related to the neck die. I will be receiving the collar to eliminate the expander ball, and we will see what happens.

    What dies are you using to get that small run-out on your rounds?

    I am using lapua brass, which gives a variance of up to .003" on the random cases I tested right out of the box. I may have to invest in a neck turning set-up. The chamber isn't a tight neck, but it is definitley not a factory chamber either.
     
  9. BountyHunter

    BountyHunter Writers Guild

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    JustC

    My 6.5/06 die is custom on a newlon blank. The 300 WSM is redding FL sizer and shoulder bump die with forester bonanza br seater. My 338 AI is Neil Jones set and my 6mm BRH (6 BR w/shoulder blown forward .180) is also neil jones. My 300 win mag is Forester BR set with JLC bushing converion and on and on.

    I only use either Redding comps, Forester BR sets with JLC (Jim Carstenson, advertises in Precision shooting) bushing conversions ($35)or Neil Jones custom sets ($275.

    You are not neck turning, I am think you will find once you buy a neck turner (get the K & M tool(Advertises in precision shooting and is best) with the carbide donut pilot, that your problems will disappear. after turning just enough to clean up the high spots measure loaded round and order a bushing .002 under loaded round size. Be sure and order the expanding mandrel to match the pilot. Use imperial die wax or a good lube on inside of necks and outside. Use power screw drivers with Sinclair shell holders for power drivers to get an even and smooth cut. If you do it by hand, it will leave grooves. Much quicker to use the B & D powerscrewdrivers with interchangable batteries. Will get about 20-40 cases per battery, so have extra batteries.

    Lapua is the best brass, and always my first choice, but even they have variances in the neck. Only way to get rid is to neck turn to at least some degree.

    Good luck

    BH
     
  10. JustC

    JustC Well-Known Member

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    Thanks BH.
     
  11. JustC

    JustC Well-Known Member

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    catshooter, this rifle will be used in 600yd and possibly 1000yd matches over the next few years. I wish to eliminate ANY variable before having my a$$ handed to me by the Big Dogs. I'm new to the competition thing, so I already have my work cut out for me. That is the reason I am so bent on getting the necks right. I will settle for a max runout of .001".

    The brass is lapua, so I figured I am starting with some of the best going.

    For whatever reason, my Redding BUSHING dies have the expander ball. It sure enough measures .284. They usually have the decapping collar in a bag inside the box, for you to eliminate the expander ball, but my set was missing that collar. Redding is sending me a new one for FREE. I told them I needed a new 6.5 collar as well, and they said, NO problem it's in the mail.
     
  12. Brent

    Brent Well-Known Member

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    Old topic but, might be of interest...

    A "FL non-bushing type" die is the only type die that will reduce or eliminate RO by sizing.

    A bushing when used in a FL or NK die floats laterally, as the bore it sets into is slightly oversize (and this oversize bore in my opinion is totally unnecessary, and can actually allow RO to form in sizing).

    The source of the RO is the first thing to look for and to correct.

    Here's the facts though; The body of the case must be held tighly (a FL die does this) before the case neck enters the neck sizing bore. The neck sizing bore must be concentric to the body bore and must not move laterally (like a bushing will) in order to force a neck with RO back to center, or into concentricity. This RO problem simply can not be corrected with a commercial neck bushing die the way they are currently machined oversize, you will need a conventional FL die to do so.
     
  13. brian b

    brian b Well-Known Member

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    Brent,
    I noticed that you are from Alaska(awesome state) but tomorrow is the shortest day of the year (dec.21st) the darkness must be playing games with your mind if you think that a standard FL die is the way to concentricity.
    Your reasoning has some merit except for the fact that standard FL dies oversize your brass then when you expand it back out is when your concentricity problems take place,I will take a bushing neck die that gives me .001 runout any day over a FL die that will stretch my brass into a waste basket prematurely.
    B
     
  14. Brent

    Brent Well-Known Member

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    Brian

    Improper die set up is what will help the brass to the waste basket, (read excessive headspace) not the dies fault though. True, factory FL dies ID's could be a little larger so brass "might" not work harden as quickly, but that is handled by annealing anyway, also the brass is far from ruined.

    Is there some reason you think you can not get concentric necks with a factory FL die if the die's neck is reamed concentric with the body?

    The bushing dies will not correct RO, and can even make it worse if any exists, twas my main point and to explain how, I believe.

    In my opinion, a die that takes bushings that float in the bushing bore is not the most desirable set up.