Ladder test results

Discussion in 'Long Range Hunting & Shooting' started by Terrytin, Sep 5, 2019.


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  1. DUSTY NOGGIN

    DUSTY NOGGIN Well-Known Member

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    id shoot each set of 3 at a separate target , shoot early to beat that mirage , i hate to say i dont think they will duplicate your original picture, you have some pretty far poi shift with just a .2 grain change in powder

    what scope and reticle are you using ??

    what was your average group size on the first seating test ??

    take shot 10 , 8 & 9 , -- has a 4.5 sd on those velocities , which is the best of any other string of three , in the whole array .. you should expect some point of impact ,yes . but, you have over an moa of shift , it just seems as there is something being overlooked , i hope you find it on your next batch
     
    Last edited: Sep 6, 2019
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  2. L.Sherm

    L.Sherm Well-Known Member LRH Team Member

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    I've seen alot of 3" groups at 300 yards with the same powder charge.
    He's on the right track.
     
  3. DUSTY NOGGIN

    DUSTY NOGGIN Well-Known Member

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    4,5,6 is almost a 5" group and a 1-1/2ish moa poi shift left of 5,6 ?? if its not the shooter or any other variable, then it will be vibration shifting that poi right?

    im in the camp were i dont wanna add distance variables to a load work up, until at least repeatable group shows up ,

    in 300 wm ? i guess its possible, is this a thin barrel ??? i say 1/2 moa poi shift in any direction ( with a .2 grain increment change ) , plus any distance variables

    try drawing a larger shape that fits your scopes reticle better at that distance
     
  4. 7mmTikkaShooter

    7mmTikkaShooter Active Member

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    Going to jump in one more time here in regards to the poi shift. Yes mirage is a factor and so is shooter error. Given the small changes in charge weights here I would lean toward those variables as being the likely culprit for much of that lateral shift. The basic theory around a ladder test though, is not necessarily lateral poi shift but looking for the vertical dispersion. The charge weights that throw shots closer together vertically are more likely to be a stable range in velocities. In long range load development this is one of the most critical variables we’re chasing. 300 yards is a bit short for seeing this dispersion (500-600 would be more optimal) but sounds like you’re limited on that. One shot per charge might give some error too. Try to run the same test 3 times. Same process, 3 targets. Hopefully after replicating it you can start to hone in on that stable range of powder charge despite what lateral dispersion you’re seeing in one target. Like I stated earlier, the addition of a chronograph will really help if it’s available. I’ve used this same method you’re using at 300 with success in the past. I think you’re on the right track.
     
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  5. L.Sherm

    L.Sherm Well-Known Member LRH Team Member

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    This^^^^^
     
  6. DUSTY NOGGIN

    DUSTY NOGGIN Well-Known Member

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    [email protected]= 11.7ish drop
    [email protected]= 12.6ish drop - 11.7ish = 1" vertical difference expected ( on paper ) add the group size of his previous seating of ?? ill guess 1" ..... totaling 2" vertical expected

    why do you think 4-1/2" high vert ?

    then, to add that. why do you suppose that even though 456 has the best horizontal also has one of the higher ES/SD's


    SNIP OF LRH DATA rev.GIF
     
    Last edited: Sep 7, 2019
  7. L.Sherm

    L.Sherm Well-Known Member LRH Team Member

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    How can you go off of ES with different powder charges and virgin brass?
    Anyway I give the OP my advice and what works for me it's up to the OP whether he wants to use it or not.
     
  8. DUSTY NOGGIN

    DUSTY NOGGIN Well-Known Member

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    im under the impression that you are a long time shooter at those longer distances & probably good enough that you are aware of the added variables, that maybe others are not

    im not necessarily against the distance , im am interested to hear your reasons why these variables arent an issue

    i can understand the idea of real world hits mean more than any chart or graph or guess ...i feel like adding charts to real world hits also validates em. in this case it doesnt look like they mesh at all,

    you can see the math in the chart to get ES/SD on a 3 round set , i did it the same for the whole array... that is all the data he has given ,

    the top 5 shots all have great sd/es but with terrible group, id be more inclined to believe he'll find something there if he deleted some of those distance variables , hes getting good ingnition
     
  9. L.Sherm

    L.Sherm Well-Known Member LRH Team Member

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    Yes hes got variables, that's why virgin brass needs to be taken out of the equation. I let targets tell me if my stuff is good or use them to look for tendencies. I'm no BR shooter but I do alot of shooting, reloading and loading development for friends and family and lucky enough to be able to shoot 500 yards out my back door.
    I've seen low ES groups not shoot worth a crap but it is nice to have it with good groups. Run some numbers 20fps makes .5 of difference at 500 yards how many people can shoot the difference consistently. Now past that it start coming into play but I see way to many people get fixated on ES instead of learning to read ladder test and targets.
    I learn something all the time that's what alot of testing will teach you, even though I've been reloading for along time the last 10 years I've gotten alot more serious about the long range aspect of it.
     
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  10. DUSTY NOGGIN

    DUSTY NOGGIN Well-Known Member

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    that makes alot more sense to me now , i have never experienced shooting out the back door , if i could load up a few fast just to check a primer .. hell id do it to

    i do my loads based on a public firing range or a 45 min drive to desert, either way will take most of a day just to do one test
     
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  11. L.Sherm

    L.Sherm Well-Known Member LRH Team Member

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    If your not testing different primers in load development your missing the boat so to speak.
     
  12. lgordee

    lgordee Well-Known Member

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    IMHO, if one is shooting 3" groups @ 300 yards, it will be extremely difficult to gain any valuable information from a 300 yard ladder test. I shoot all of my ladder tests at 300 yards. Below is a 300 yard ladder test from one of my favorite hunting rifles that has a #3 contour barrel. Also a pic of a 300 yard 3 shot group. I think one can gain meaningful information from this scenario. Another tip is to dial off to the side from the target bullseye so as not to affect your aiming point.
    IMG_20190910_135933452.jpg IMG_20190910_140740626_BURST000_COVER.jpg
     
  13. Wedgy

    Wedgy Well-Known Member

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    Scrap that and shoot the Berger 215 grain with H1000 you will be closer to 3,000 fps, work up from ~72 grains.
     
  14. L.Sherm

    L.Sherm Well-Known Member LRH Team Member

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    If hes got the freebore I agree.