286 gn swift aframe 9.3x64

Discussion in 'Reloading' started by bruce moulds, Dec 23, 2018.

  1. bruce moulds

    bruce moulds AH Elite

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    load testing today produced these results.
    as usual these are for my rifle with my components on this day so approach with caution from below.
    velocities are from the same labradar as my previously reported 300 gn swift loads.
    powder is ar2209, sold in the rest of the world as h4350, and is noted for temp stability.
    it is reportedly a smidge slower than imr4350, but very close.
    primers are fed 215.
    72 gn 2508 fps.
    73 gn 2567 fps
    74gn 2587 fps
    75gn 2610 fps.
    the 72 gn load shot to the same elevation as 70 gn with the swift 300 gn bullet.
    each increment printed the bullets higher, such that the sight setting for the 286 gn gn bullet at 2587 (74 gn) when 3" high at 100 will print the 300 gn bullet at 2400 1" high.
    this could be useful.
    bring the 300 gn bullet up to 2500 fps and it will shoot to about the same elevation as the 286 at 100.
    the 286 gn and 300 gn swifts are about the same length, and so the lighter bullet is made so by increasing the ogive length.
    this raises th b.c. enough that the lighter bullet has a slightly higher b.c. than the heavier one.
    the longer ogive length comes from shortening the bearing surface.
    this translates to more bullet jump for the 286 when both bullets are loaded to mag length.
    i wondered if this jump night affect accuracy but did not seem to.
    lighter bullet, higher b.c., faster = flatter trajectory.
    the 286 gn still has an s.d. of the magic 0.3, so it will be a big game killer.
    in fact bill hober told me that i might not notice the difference in that area from the 300 gn.
    none of my loads were anywhere near max, but going higher would be an unpleasant experience in my lightish rifle.
    the increase in recoil from min to max above could be falt noticeably.
    bruce.
     
    Nkawu likes this.

  2. bruce moulds

    bruce moulds AH Elite

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    looking at my targets again.
    the 2 lighter loads printed about the same elevation, then the poi climbed a little over 1 moa per grain.
    this raises the question of nodal activity.
    the 2 lower loads might well be in a node, which raises the question of whether there is another node at higher charges.
    the highest load i tried was not up to claimed factory velocity, and was quite safe.
    repriming the fired cases revealed tight primer pockets.
    if factory loads are as advertised they might have chosen that level of performance due to a safe node there?
    for now i have loaded all my cases with the 286 gn bullet at 74 gns , balancing recoil, case life, unwanted surprises, and reliability in all weather.
    this level of performance (2587fps) is close to the 2600 that was the goal, and grouped well.
    seeking a higher node, if there is one, well above 2600 but less than 2700 will be an interesting pursuit for the future.
    bruce.
     

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