calculating sight adjustment

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    toppkatt

    Ultimate Member
    Apr 22, 2017
    1,199
    Just got a new tang sight for my .45 70 lever gun. Trying to figure out what adjustment I have to make going from a 200 yard target to 300 yards assuming bullet drop of approximately 54 inches from 200 yards to 300 yards. Each click raises the peep up 0.004 inches. The distance from rear peep to front sight is 33 inches, if that is needed. The front stays the same sight. What formula should I use?
    Thanks
     
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    toppkatt

    Ultimate Member
    Apr 22, 2017
    1,199
    Well I was pretty dang close! At 200 yds my clicks were 80 total. At 300 yards I had to come up to a total of 117 clicks or a total of 37 clicks up elevation. Close to the 41 or 42 I calculated. Guess it didn't drop the full 54 inches I was expecting. My reloads must be slightly hotter than I initially presumed. Interestingly, the Blackhorn 209 shot a little faster then my smokeless load using IMR SR4759 (no longer manufactured).
     
    Biggfoot44

    Biggfoot44

    Ultimate Member
    Aug 2, 2009
    33,274
    The exact values will vary slightly depending upon the exact sight radius , but most click adjustable metallic sights are designed for a nominal MOA value .

    0.5MOA is typical , 0.25 MOA is extra precise, 1.0 is pretty coarse .

    Depending upon sight radius , a nominal 0.5 could range between 0.4 and 0.6 hypothetical , but 0.5 will put you initially in the ball park .
     
    T

    toppkatt

    Ultimate Member
    Apr 22, 2017
    1,199
    The new tang sight worked as expected. The longer stalk allowed me to not need 4 feet of hold over at 300 yards.
    Managed to do okay last Sunday,in the snow and wind, taking first in smokeless and first in blackpowder. Missed high overall by 4 points. But my 300 yard shots were pretty good (5 for 5 rams with smokeless and 3 for 5 with blackpowder). Now if I could just hit those turkeys @150 yards... That's where I really lost the match.
     
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