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7mag/H1000 ladder interpretation

Discussion in 'Handloading and Reloading' started by syhunt, Oct 17, 2019.

  1. syhunt

    syhunt Member

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    Good Mernin' folks. I'm looking for some help analyzing results from my first load development (pictures attached). Short story long I was looking to mimic velocity/accuracy from a Nosler factory load. Sifting through the various load development techniques I decided to try the 10 shot ladder method looking for the accuracy nodes. Nosler didnt have any published data on H1000 with the 160 AB so I went to my Lyman manual. Working in 0.6g increments I shot (2) 10 round strings and recorded velocity with magneto speed. Unfortunately coloring the bullets did not show up on the target so I have to rely on velocity for this test. I'm not sure where to take it from here.

    Rambling thoughts/notes:
    1. In general the second string was hotter, likely due to warmer barrel.
    2. Possible accuracy node in the 67g - 67.6 although its clear as mud. If this range proves to be most accurate are those velocities/es acceptable for a 7mm mag primarliy used for a mule deer/aoudad gun in the 300-500yrd(max) range?
    3. ES (with the exception of shots at 68.8) from 68.2g to 70g was tight but no accuracy node here.
    4. Nosler factory load averaging 3035fps and 3052 ( with 69.8gr of a mystery flattened ball powder)
    5. No viable pressure signs, but 70g was max load from Lyman and 4g over max load from Hodgon website. Its possible the bolt might've been a little tighter at 70g but that could be psychological knowing I was at a max load and over another.
    6. Would've liked to shot the 3rd string I loaded up but ran out of time.

    Alright guys I'll let yall take it from here.

    Thanks, ladder test.JPG ladder test data.JPG
     
  2. Bfh_auto

    Bfh_auto Member

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    From 64.6 to 65.8 had the least velocity increase, so I wouldn't be surprised if you found good accuracy there.
    But, I would need the point of impact change for each shot.
    Similar velocity means nothing if it's at a bad spot in the barrel vibration.
     
  3. climbnjump

    climbnjump Member

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    Your two shot strings have given you a nice velocity trend, but I gotta admit, I don't know how you might be identifying an accuracy node from just two shots at each charge weight. As my grandpa used to say, statistically, that's "pretty thin".

    But for the second part of the quote, yes that would work at 500 yards if you can put the bullet where it needs to be. You'd still have about 2100 fps and about 1500 ft-lbs of energy which would be about the same as my grandpa's thutty-thutty at 50 yards.
     
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  4. syhunt

    syhunt Member

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    @Bfh_auto you're probably correct. I wasn't considering 2800fps and hoping I can do better (2950-3000?) and find some some accuracy....but as you guys always say..velocity isnt everything. Out of the box the rifle shot 1/2 moa @ 100, with two different factory loads so it will be apparent quickly if the gun doesn't like what it's fed. I uploaded a quick picture of the target from that day. As I mentioned above my colored bullets didn't leave any noticeable mark so it was tough to see what was what and didn't have time to reel the target home after each shot. Being a first timer its hard to discern anything, I target.jpg figured the dispersion would be greater but its all within about 1.5".
     
  5. Walkalong

    Walkalong Moderator

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    Certainly worth loading five or ten and shooting a group at 67.
     
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  6. Bfh_auto

    Bfh_auto Member

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    A trick I learned, was take an extra target and a package of colored markers.
    Each shot is marked on the spare target with a legend on the side for color coordination.
    For a huge charge variation, that's not bad. It means you should have a good node somewhere.
     
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  7. climbnjump

    climbnjump Member

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    Which day was the target shot? The factory load day or the ladder test day?

    I know bullets can share the same hole - I mean, that's what we all want, right - but it just doesn't look like that target had 20 bullets from a 6 grain spread ladder test shot at it from 100 yards.
     
  8. syhunt

    syhunt Member

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    1/2moa day was a different day. First picture I uploaded was the first 10 shot string. Here’s the 2nd that opened up some, I just don’t remember much about it I was getting rushed. The 3 shots on the bottom left are warm barrel factory shots.
    36DCFF2D-C0A1-42FE-A305-1CB5EC30F635.jpeg
     
  9. Varminterror

    Varminterror Member

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    Smaller rungs on your climb would help. Pick a portion you’d like to zoom in on and shoot smaller increments there. I’m guessing there’s something near the top end there too which might make you happy, if you dig for it.
     
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  10. climbnjump

    climbnjump Member

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    First, even though Nosler doesn't list a load for H1000 for that bullet in their manual, they may still have data for it, so give them a call to find out.

    Next, as you probably already know, it may not be possible to achieve the same velocity with your handloads that you saw with the factory loads. Sometimes they are using powders that aren't available to us mere mortals.

    Then, when shooting a ladder test, it's best to shoot all loads of a given charge weight at the same point of aim. For instance, the targets you uploaded have 5 aimpoints so you could shoot 5 different charge weights on the same target. So for instance, load 3 (or more) at, say, 65.8 gr and shoot them at one aimpoint. Then the loads at 66.4 gr at the next and so on. You can still shoot the entire batch round-robin if you'd like, but keep the same charge weights on the same aimpoints for accuracy comparisons.
     
  11. syhunt

    syhunt Member

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    Thanks for everyone's input. Still thinking but since i have 10 rounds already loaded I will most likely shoot them and take data the same way as the first two strings. Might be able to pull some ES and accuracy by having three data points. After that I'll have 30 cases fireformed cases so I can pick a smaller range and proceed as @climbnjump and @Varminterror mentioned. Question for you guys: What should I expect going from new unformed brass to formed and sized brass if charge weights/seating depth are kept constant? Hornady bushing die is set up for 0.0015 bump and 0.003 neck tension.
     
  12. Varminterror

    Varminterror Member

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    Not enough change to be perceptible within those groups and velocity spreads. I generally like to recheck/correct/confirm my seating depth after fireforming, but other than that, nothing changes from new brass to fireformed.
     
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  13. GTS Dean

    GTS Dean Member

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    I usually ladder at 0.4 gn over the recommended range. I load 4-round groups and make sure the bullets are seated to the same cartridge ogive depth. I use a different target aim point for each group of 4, as below.
     

    Attached Files:

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