Measurment of Accuracy

Discussion in 'Rifle Talk' started by The_Cook, Sep 21, 2005.

  1. The_Cook

    The_Cook Guest

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    Well I've just finished reloading my second go around of brass. Now that I am comfortable with the process of reloading..... 200rnds of hand made ammo! :D :? :) :D :lol: :twisted:

    I would like to start messing around with the current powder that I use (H4895) and use different grain weights.

    The question is......
    What is the minimum amount of rounds I need to establish grouping? 3/5/10 etc.? If someone can give me a ballpark I can then quickly go through many different powder weights.

    One more thing......
    By how many grains should I vary my loads to notice a difference between each? .1/.3/.5/1.0/2.0 etc.?

    Any advice that can be given on these subjects will be greatly appreciated
     
  2. mountainview

    mountainview Super Member

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    If you really want to go whole hog, grab a statistics textbook, read it, apply some of the methods and do some full blown hypothesis testing. Depends on how good of a statistical average you want. 3 is ok, 5 is optimum IMO, and 10 would be statistically rigorous but overkilll for the average bloke testing home rolled loads.

    For small capacity cases, increment in .1 grains, larger capacity cases, increments of .5 grains are generally ok. Sorry but I forgot what the definitions of small and large cases are. Do not exceed max load in any case.
     

  3. grimel

    grimel Guest

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    First and foremost follow the reloading manual guidelines.

    After that, what ever makes you feel good. For big game rifles (mostly the deer family, hogs, and black bear) I have rather exacting standards - a good bullet that shoots < 1.5in an 100yds at 2700 fps or better at a less than max load. That's it. Write it down and don't fool with it anymore. Pistols - heavy bullet at max velocity that keeps it 2" or less at 100 (straight walls) or 1" (bottlenecks). Varmit rifles is where it gets to be a "pain". I'll fiddle around in 0.1 gr steps until I find something that prints 1 hole groups. I load 5 at each step and recheck anything that looks to have potential. When I find a servicable load I buy a LOT of primers from that lot and all the powder from that lot I can afford. If I'm near a max load when I run out I step down with the new lot(s) and work back up. USUALLY nothing changes, but, if it' a low use gun and the powder formula has changed the step down and work up can save either the rifle or possibly you damage.

    One last thing, I weigh every 5 charges in bottle necks unless I'm at a max load then I weigh EVERY charge. That's one reason I try to stay away from max loads along with longer brass life, easier on the $$, easier on the shoulder, and USUALLY better accuracy.
     
  4. The_Cook

    The_Cook Guest

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    Good advice from both of you. Thank you very much