Advise please

Discussion in 'Long Range Hunting & Shooting' started by lefty15, Jul 31, 2007.

  1. lefty15

    lefty15 Well-Known Member

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    I hunt exclusively on flat land, but this fall I will be hunting for deer in rough hilly terrain, and I will have to at some point make an up hill shot or a down hill shot.
    I shoot a .300 win mag and I am 2" high a 100 yards, so when shooting up hill or down hill will the POI be the same or will I have to shoot high or low?
     
  2. gbp

    gbp Well-Known Member

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  3. jwp475

    jwp475 Well-Known Member

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    Shooting up hill oe down hill the trajectory will be flatter....How much flatter depends on the angle and the distance.....
    Acosine indicator will allow one to know the angle and balistics program will give the correction...........


    [​IMG]
     
  4. lefty15

    lefty15 Well-Known Member

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    The ranges that I will be shooting at will be from 0-500 yards at max. I guess the problem that I have is that I do not have a scope with target turrets or a cosine indicator. I shoot a .300 win mag with 168gr Barnes TSX bullets with a Leupold VXII with a heavy duplex reticle.
    I am very confident with my rifle shooting out to 500 yards, but I am unsure of whether I should be shooting below or above a animal at say 300 yards shooting either up hill or down hill.
     
  5. Len Backus

    Len Backus Administrator Staff Member

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    Lefty

    I'll let others go into the exact calculations, but out to 500 yards there won't be more than a couple of inches of change in POI unless your uphill/downhill angle is a lot more than 20 degrees...which is really pretty steep for most western hunting in hilly country at a distance as great as 500 yards.

    To correct, you would aim those couple of inches lower than normal. The reason for this is that the gravity vector operates on the bullet in a direction not quite perpendicular to the bullet's flight. Therefor the bullet doesn't drop quite as fast as it traverses the 500 yard distance.

    Think of it this way. Hold your right arm out parallel with the ground while hanging a 20 pound weight from your hand. Notice how much effort it takes at this angle. Now move your arm's angle to be 45 degrees. You'll notice it takes less effort to hold the same 10 pound weight.
     
    Last edited: Aug 1, 2007
  6. 300rum

    300rum Well-Known Member

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    Hi Lefty,

    Can you give me the conditions to run them in ballistic program to find your bullet drop:
    round grain - 180
    bullet BC -
    temperature -
    elevation (ft) -
    muzzle speed (fps) -
    distance < 500yards
    angle cosine -

    As Len mentions, you do not suppouse to have big drop when you are shooting up or down hill not more then 20 degree at that distance, but is better to check just in case....

    Thanks Chris
     
  7. lefty15

    lefty15 Well-Known Member

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    Hey Chris here is the info, thank-you very much for the help!

    round grain - 168GR BARNES TSX
    bullet BC - .404
    temperature - 32F
    elevation (ft) - 3200FT
    muzzle speed (fps) - 3200FPS
    distance < 500yards- 300 YARDS
    angle cosine - ??????
     
  8. 300rum

    300rum Well-Known Member

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    ___________
    ok here are

    Range Angle Angle Angle Angle Angle Angle Angle Angle Angle Angle Angle
    [yards] 0 5 10 15 20 25 30 35 40 45 50
    0 0 0 0 0 0 0 0 0 0 0 0
    50 50 50 49 48 47 45 44 41 39 35 32
    100 100 99 98 96 94 90 87 82 77 70 64
    150 150 149 147 144 141 135 131 123 116 105 96
    200 200 198 196 192 188 180 174 164 154 140 128
    250 250 248 245 240 235 225 218 205 193 175 160
    300 300 297 294 288 282 270 261 246 231 210 192
    350 350 347 343 336 329 315 305 287 270 245 224
    400 400 396 392 384 376 360 348 328 308 280 256
    450 450 446 441 432 423 405 392 369 347 315 288
    500 500 495 490 480 470 450 435 410 385 350 320
    550 550 545 539 528 517 495 479 451 424 385 352
    600 600 594 588 576 564 540 522 492 462 420 384
    650 650 644 637 624 611 585 566 533 501 455 416
    700 700 693 686 672 658 630 609 574 539 490 448
    750 750 743 735 720 705 675 653 615 578 525 480
    800 800 792 784 768 752 720 696 656 616 560 512
    850 850 842 833 816 799 765 740 697 655 595 544
    900 900 891 882 864 846 810 783 738 693 630 576
    950 950 941 931 912 893 855 827 779 732 665 608
    1000 1000 990 980 960 940 900 870 820 770 700 640
    1050 1050 1040 1029 1008 987 945 914 861 809 735 672
    1100 1100 1089 1078 1056 1034 990 957 902 847 770 704
    1150 1150 1139 1127 1104 1081 1035 1001 943 886 805 736
    1200 1200 1188 1176 1152 1128 1080 1044 984 924 840 768
    1250 1250 1238 1225 1200 1175 1125 1088 1025 963 875 800
    1300 1300 1287 1274 1248 1222 1170 1131 1066 1001 910 832
    1350 1350 1337 1323 1296 1269 1215 1175 1107 1040 945 864
    1400 1400 1386 1372 1344 1316 1260 1218 1148 1078 980 896
    1450 1450 1436 1421 1392 1363 1305 1262 1189 1117 1015 928
    1500 1500 1485 1470 1440 1410 1350 1305 1230 1155 1050 960
     
  9. lefty15

    lefty15 Well-Known Member

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    Hey Chris thanks but I am a newbie here can you please explain your chart?
     
  10. davewilson

    davewilson Well-Known Member

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    Len, i'm sorry but i have to disagree with your answer as to why the bullets impact higher when shooting on an angle. gravity has nothing to do with it. the reason the bullets impact higher is because of the vertical difference of the centerline of the barrel and the line of sight when they're at an angle as compared to horizontal.
     
  11. 300rum

    300rum Well-Known Member

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    Hi Lefty,

    on base of your bullet info, I just generate a drop table from 0 - 1500yards.
    So - first column = distance of shooting
    from the 2nd to the last column is how you will aim at that distance.

    examples:
    so you are hunting on hill side of the mounting and you spot an animal.
    Ranging the distance with a rangefinder and you read - 400yards
    if you are shooting strait (no uphill or downhill) - you will aim as you are shooting for 400yrds.
    if between you and the animal is 5 degree slope = you will aim as you are shoting at 396yrds
    if between you and the animal is 10 degree slope = you will aim as you are shoting at 392yrds
    if between you and the animal is 15 degree slope = you will aim as you are shoting at 384yrds
    if between you and the animal is 20 degree slope = you will aim as you are shoting at 376yrds
    if between you and the animal is 25 degree slope = you will aim as you are shoting at 360yrds
    and so on...
    JUST SEE THE TABLE.

    400 400 396 392 384 376 360 348 328 308 280 256

    as you see from zero to 20 degree slope is almost no need to use corection of shooting at big game.
    but passing 20 degree slope you have to do aiming corection, if not you will miss shooting high on top of the target. With how match? Just see the tabel.

    I hope this helps.
    chris
     
  12. lefty15

    lefty15 Well-Known Member

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    Thanks very much Chris, this will be a great help. So this drop table will work for either uphill or down hill shooting?
     
  13. 300rum

    300rum Well-Known Member

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    Yes, for both you have to aim the same.
     
  14. 300rum

    300rum Well-Known Member

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    Yes, for both you have to aim the same.