A big question about extreme spread

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Lazerus, Aug 21, 2013.

  1. Lazerus

    Lazerus Active Member

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    Dec 30, 2011
    Thanks to everyone who has responded to all my various posts, i appreciate it alot, they have been helpful! I will quickly cover the basics,;
    I am shooting a 6.5 284 Norma built by Ryan Piearce of Precision Rifles, LLC It is printing now, 1/4 inch 3 shot groups at 100 yrds. I wont have access to longer ranges for another month. My main question deals with extreme spread. I am shooting H4831SC with 52.8 grains. The 140 grain Berger VLD at 10,000ths down from full jam. I have been reloading this ammo as meticulously as possible, weighing out each charge. My extreme spread is 2980, 2957, 2980, 2985, 2963, 2981, 2964. I was puzzled as to why my loads were not more uniform in speed. I got alot of great suggestions from people here. I think I may have one of the answers, but would like a bit of input. One of the things that has puzzled me, is my cartridges vary in how they fit the chamber. I know this, because when I lower the bolt, sometimes it is fairly easy and sometimes it is fairly difficult to close. I think the reason is I have been sizing the body then sizing the neck. I think that this is probably an inconsistent way to size. When I size the neck last, it will probably pull the shoulder forward, on some more than others. I have now been resizing the neck first, then the body, which is giving me a uniform cartridge and the bolt feels identical each time. I will confirm at the range this weekend, but I was just curious if anybody thinks this might be the reason for my extreme spread.
     

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  2. MontanaRifleman

    MontanaRifleman Well-Known Member

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    May 21, 2008
    Congrats on your good shooting and a good shooting rifle. I would be very happy with that.

    As for your ES, how do you know your velocity readings are accurate? What chrony are you using?

    As for reloading, I used to do the 2 step neck and body sizing process also. Then I asked myself why do this in 2 steps instead of one. A few years ago I called Redding and talked to one of their highly experienced tachs about a couple of things and we got into a convesation about different type of sizing dies including Neck, body, competition, type S bushing and standard FL dies. He told me that in his experience the standard FL die was the best for concentric and consistent sizing. I ordered one for my RUM that week and it consistently produces sized cases with less than .001 of runout, and that is with unturned necks which will have some variation in them.
     

  3. 8andbait

    8andbait Well-Known Member

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    Jan 14, 2012
    Did you get the type D die? Have you honed the die so it doesn't size down too much? Are you using the expander button?

    Thanks