Precision Reloading For Long Range Hunting by Jerry Teo

Discussion in 'Technical Articles - Discussion' started by Len Backus, Oct 9, 2007.

  1. Len Backus

    Len Backus Administrator Staff Member

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    This is a thread for discussion of the article, Precision Reloading For Long Range Hunting, by Jerry Teo. Here you can ask questions or make comments about the article.

    The author will have this thread automatically notify him of posts so that he can join the discussion.
     
  2. James H

    James H Well-Known Member

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    Jerry
    Excellent article and I am in 100% agreement with most of it.
    There are a few things I do different though. I do use a Lee hand primer on occasion but I don’t get the feel I get with my RCBS bench primer. Honestly it’s to the point that it pisses me off every time I use the Lee primer, but then I have used the RCBS for over 30 years and only got the Lee in the last couple so maybe that has something to do with it.
    I like either a full length bushing die or a full length die that has had the neck reamed for the proper neck tension. Like Jerry I do not like having the expander ball pulled through the neck after resizing, it can cause crooked necks.
    With moderate loads the Lee collet dies work great but with hot loads the case really needs to be FL sized each time for easy chambering. Jerry’s idea of using the body die with the collet die is great though if you want to run the cases through the die twice to resize, and there’s nothing wrong with that. I also do that when using the Redding competition neck sizing die. I also I still use the Lee collet die with a few rifles too. If you load light enough that you don’t need to FL size it sure is great to not need to remove resizing lube.
    I’ll give this article 5 stars and 2 thumbs up.
    Good job Jerry
    James
     

  3. Mysticplayer

    Mysticplayer Writers Guild

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    good stuff

    James, thanks for the complements on the article.

    I do use FL sizing dies for a few cartridges and been lucky, no runout. Where I find FL sizing to be necessary is in big boomer magnums.

    Even though my smaller cartridges are run at similar pressures, they don't expand as much as cases like the RUM. The 223 can take all manner of abuse before needing to be shoulder bumped but the RUM needs FL sizing everytime. The RUM rifle has no headspace issues.

    My guess is that the amount/duration of pressure is more severe in the larger case leading to more 'permanent' change in the case. The smaller case has the same/similar peak pressure but less of it so the brass can take more shots before growing.

    Just a SWAG theory.

    At any rate, function in the field is paramount so size the cases to ensure 100% function.

    Jerry
     
  4. eyedoc

    eyedoc New Member

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    Great article. I am fairly new to reloading, what do you mean by runout?
     
  5. AJ Peacock

    AJ Peacock Well-Known Member

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    Welcome to the site. Check out this thread
    http://www.longrangehunting.com/forums/f28/bullet-runout-21354/

    Runout is essentially how straight your reloaded round is. If your chamber is perfectly straight/square and the brass is perfectly consistent in thickness (not gonna happen) then straight rounds are easy to make.

    Runout is measured in 1/1000" of an inch with fixtures like this, Concentricty Gauge

    With good brass and good processes, you should be able to get .002" or less runout.

    HTH

    AJ
     
  6. devildoc

    devildoc Well-Known Member

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    Runout refers to the bullet not being completely centered in the cartridge case, major culprits being crooked, out of round necks and poor bullet seating.


    Great article, never thought about the case weight versus volume thing, and I think you're dead on with that, if I ever get that anal with my brass, I'll measure volume not weight.

    I however don't think that the CCI primers not showing pressure signs is a good thing. They're just harder and don't show it, doesn't mean the pressure isn't there. I much prefer the federal primers for that reason, I can tell when I'm pushing max pressure when my primers start to flatten a bit, with the CCI's you might see extractor flow at almost the same time as those hard things start showin' you anything.
     
  7. Mysticplayer

    Mysticplayer Writers Guild

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    I have always found that the CCI primer showed pressure signs before the extractor marks showed up.

    With the common practise of removing any slop in the action lockup, 'safe' chamber pressures have increased. I am not saying a huge increse, but definitely to the magnum+ range. Many of todays powders burn their best at magnum or slightly higher pressures. Low velocity variations and greatly reduced stringing are usually the benefits.

    That provides a huge benefit in giving us accurate ammo for LR hits.

    The CCI primer will not let get you to the point of locking up or grenading your action, but it will allow for a few more PSI's before flattening out when compared to the Fed.

    Why is reducing runout important? Imagine that the bullet is 'crocked' as viewed down the bore. That bullet now engraves in the lands with the point off center. As it spins and leaves the barrel, it will fly wobbly like a poorly thrown football - each end wobbling around the path of flight. Pin point accuracy isn't going to happen.

    The closer you can get that bullet centered on the rifling the more true the bullet will spin as it leaves. This reduces dispersion/inaccuracy at distance.

    Jerry
     
  8. stephen newberry

    stephen newberry Member

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    Precision Reloading by Jerry Teo

    How can I get this info

    Thanks Stephen
     
  9. Jerry M

    Jerry M Well-Known Member

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    I like the idea of using powder to measure case volume instead of weighing cases.

    Thanks

    Jerry M
     
  10. James H

    James H Well-Known Member

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  11. Boss Hoss

    Boss Hoss Well-Known Member

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    If you are really interested might look into attending the class that Speedy is giving----you will learn what to do and more importantly how each operation relates to the end result... When you get finished your knowledge base will be expanded.. Week 3

    [​IMG]
    [​IMG]
     
  12. aitch

    aitch Well-Known Member

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    Neck turning

    Excellent write-up! I have a question about neck turning.
    You suggest neck turning to clean up 70-80%. I would think turning to a specific diameter would provide more consistant results.
    How does neck diameter relate to throat diameter?
    How do you determine throat diameter, chamber cast?

    Thanks
     
  13. Mysticplayer

    Mysticplayer Writers Guild

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    With hunting ammo, I do not like having my necks thinner then 14thou. Simply reduces the chances of neck splits or bullets slipping. This ammo has to work first and foremost.

    With US commercial brass, there can be a slight variation in the thickness as you go around the circumferance of the neck. Is this a big deal? Not really but since we have the tools why not just tweak it.

    By removing the high spots, the neck is of consistent thickness yet still thick enough to offer the higher neck tensions needed in mag fed ammo. Odds are you will find it hard to see any accuracy improvements on paper but it makes me sleep better.

    Consistent neck thickness helps with consistent neck release which helps with bullets leaving straight so they enter the bore square with the rifling and fly straight to the target. Proper annealing is just as important as neck thickness.

    ALL hunting chambers should have enough neck clearance in the throat so that a bullet will easily fall into the neck after firing. If not, removing some material from your case neck or enlarge your chamber. The last thing you want is for a bit of moisture to get on your ammo and cause a serious pressure problem by jamming up the case neck in the chamber.

    I see a number of people building to BR clearances - actions and chambers - in a hunting rig. BAD IDEA!!!! Sooner or later, moisture or dirt will enter into the equation and there will be some serious problems.

    We are optimizing the hunting rifle and ammo, NOT making a BR speced hunting rifle.

    Jerry
     
  14. aitch

    aitch Well-Known Member

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    Thanks for the clarification. You remove enough material to uniform the OD without thinnng the more than .014". The fit criteria being a free drop into the chamber after firing.
    I've reloaded for many years without neck turning but now that I'm gettng started in long range, I want to understand better what I've taken for granted for so long.
    I'll be getting a custom 6.5 x .284 in a week or so and want to move my reloading techniques to a higher and more precise level. Thanks again.