Adjusting scope for range

Discussion in 'Long Range Hunting & Shooting' started by Timberman, Nov 23, 2005.

  1. Timberman

    Timberman Member

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    Please forgive me for asking newbie questions. I'm very interested in extending my shooting ranges out beyond 350 yards, and am trying to figure out some ideas in theory before I just start shooting. I just bought my first zeiss scope, a diavari vm/v 3-12x56 with illuminated heavy duplex. I've saved for 4 years to buy this thing. I put it on my accumark 7STW. Shooting factory loaded 140gr. ballistic silvertips. The scope has adjustments in centimeters, 1 click = 1cm at 100 meters. I've got it sighted 3" high at 100 yards, which should give me a 312 yard zero, according to a ballistics program I downloaded. With all that said...

    If I wanted to shoot a target at 500 yards, the program says my impact will be roughly 20" low. 20"=50cm. So I would adjust the scope up 10 clicks, right? 10 clicks = 10cm at 100m, and 50cm at 500m. Is this the method you all use to adjust for range?
     
  2. Jon A

    Jon A Well-Known Member

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    Personally I'd just skip the hole converting from inches to cm then back to inches again, and just print out the drop chart in MILs. Your scopes clicks are 1/10 MIL. If you don't have a program that can do it, go to the sticky with downloadable ballistics programs and give Dave King's a try. For example, if it says 1.2 under "MIL DROP" for 500 yds you'll need 12 clicks.
     

  3. Timberman

    Timberman Member

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    Thanks Jon A
    That's what I was looking for!
     
  4. Jon A

    Jon A Well-Known Member

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    No problem. One note--Dave's spreadsheet needs the zero range to be in multiples of the range increment (so if the increment is 50, a 300 yd zero works while a 312 yd zero won't). If you don't want to base off a 100 yd zero, I'd suggest using 300 even and actually zeroing the rifle at that range.

    After paying a little more attention you the load you're using and entering it, I'm showing about 1.1 Mils or 11 clicks at 500 yds, just using 1000 ft altitude since I don't know where you are.
     
  5. sscoyote

    sscoyote Well-Known Member

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    Timberman-- if u're just going out to 500 u may also be able to use the reticle itself as a sort of 1 stadia ballistic reticle. If u're interested i can check my info at home tomorrow, and see what the subtension is between the x-hair and the lower post of your plex reticle (i'm at work now). I'm showing your drop to be 3.75 MOA at 500 yds. with a 312 yd. zero. Actually here's what i get for all your drops in 50 yd. increments--

    312=0

    350= -.75 MOA

    400= -1.75

    450= -2.75

    500= -3.75

    Suppose the reticle's lower post tip is 3.9" below the x-hair at 100 yds. To calculate MOA divide by 1.05, or

    3.9/1.05 = 3.75 MOA

    Of course, this means that the lower posts zero= 500 yds. Here's how the system would work to reference the other ranges along the vertical axis between x-hair and lower plex post tip--

    450 = 2.75/3.75 = .7 of the distance from the x-hair to the lower post, and we can now finish the range chart as follows--

    350 = .75/3.75 = .2

    400 = 1.75/3.75 = .5


    Here's what the range sticker would look like--

    312-0
    350-.2
    400-.5
    450-.7
    500-LP

    It's just another alternative (tho admittedly not quite as accurate) to clicking if u want something that's just slightly faster. Fun to play with too. U can do the exact same with 10 mph wind using the horizontal plex post tips.
     
  6. Guest

    Guest Guest

    Theory?

    Here's a good theory! Get you a 4.5x14x50MM Leupold with target knobs, zero at 200 yards, loosen the three Allan screws that holds the "barrel"(the round tube on the knobs with numbers on it) in place, rotate it to "0", retighten the Allan screws, and then obtain zeros all the way back to wherever and record the zeros as you go! For in-between distances, you can come back and interpolate very close or actually shoot to confirm!!

    I've been using this "theory" for many years and it never fails to work!! Ballistic programs are fine...for getting a "general idea" for what your bullet may be doing at various distances but there's ONE BIG BUT...in using them which is that the program doesn't take into account the harmonics of your individual barrel! One barrel may be exiting the bullet on a down node; the other an up node!

    FWIW!!
     
  7. Timberman

    Timberman Member

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    Man, I just took a Vari-X III 4.5-14X50 off that gun. I was having a really hard time seeing deer in the last few minutes of shooting light at 250-300 yards. Saw some huge bucks last season with my little zeiss bino's, but couldn't get on them with the scope. I have high hopes for this new scope. The leupold went on my Rem. 700HB in .243 win. She's bad! I will look into some target knobs for it and play with it some, there are plenty of crows and foxes that need managing on this same farm. It works fine for deer too, as long as you're really precise with your shot placement.

    I used the eskimo ballistic table, my computer kept getting errors on all the other programs I tried. I printed out mils for range, and wind drift in inches (5mph up to 20) out to 600 yards and taped it on the rifle. Not that I'll be shooting that far. I'm going to have to make a steel target and work with this gun, see what it really does. The card will get me in the ballpark though. I don't understand the MOA/Mildot stuff yet, I need to do some reading. I found a shooting simulator online last night, and might get that to play with. It is harder for me because I don't reload and I don't have a range close by to shoot on. Someday though.

    Thank you all for the info, it has helped me alot. I thought I knew something about shooting before, but I've only begun to realize how much I don't know. /ubbthreads/images/graemlins/laugh.gif
     
  8. Guest

    Guest Guest

    Yeah...I despise them damn Leupold scopes! Been shootin 'em all of 50+ years and can't see crap wif 'em! Been thinkin bout replacing the 21 of 'em I've got but my banker just don't think kindly bout loanin me $30,000,00 to replace 'em with those OTHER scopes whut see so good! He told me when it gits to where I can't see past 500 yards real late...ta just come on to the house cause the cornbread be a gittin cold! Damn...reckon I'm jist gonna havta start killin 'em in the middle of the day....while I kin still see goodenuff!! /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/frown.gif
     
  9. Guest

    Guest Guest

    Timberman

    Whut ya needs to do is send that scope on ta me fer bout half price cause ya done tole me ya can't see nuthin wif it so I'll be real kindly ta please ya ta jist take it offen ya hands!! Bout $175.00 be all it's wurth anyway!! /ubbthreads/images/graemlins/grin.gif
     
  10. Timberman

    Timberman Member

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    It's a good scope, just isn't what I need on this rifle. You have to turn it down so low to gather enough light that you can't see the deer. Glad you like yours, I'm going to try something else on this gun this year. If the zeiss doesn't work out right I'll try a nightforce, I guess.
     
  11. Jon A

    Jon A Well-Known Member

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    It'll work fine. In the end, what difference does it really make what the click values are? The ballistics program gets you just as close either way, you shoot at the distances and verify the number of clicks. What difference does it make if that's 15 1/4 MOA clicks or 11 1/10 MIL clicks?

    Actually with a Mil dot reticle, I'd prefer the 1/10 MIL clicks so I could forget about MOA all together. It's really a tomAto, tomOto thing as far as I'm concerned.
     
  12. sscoyote

    sscoyote Well-Known Member

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    Timberman, regardless of whether u have reticle 80 or 88, as far as i can see neither would provide any tactical application since the subtensions r too big at 140cm/100m post tip to post tip. Oh well looks like it's clicking or nothing. Windage would work to some degeree by knowing the dimensions of your target, and referencing wind on the target itself.
     
  13. Timberman

    Timberman Member

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    I appreciate you checking on that for me. I'm not really hoping to make this rifle into a LR rig like some of you all shoot, but I would like to be able to kill deer out to maybe 500 yards max, and routinely at 400. The leupold I had on it before was great, but every year I'd see these big deer in the last couple minutes of legal light and couldn't shoot, but could see them clearly in the little binos. That will frustrate you terribly. I'm sure this rig will do what I need it to do, I'll mess with it and compare actual shooting to the range card. Tomorrow is our rifle opener, we'll see what happens.
     
  14. long action

    long action Well-Known Member

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    I know they are not to popular on this board, but I love my three Horus Visions. No clicking. just like reading a road map. I know they are intimidating at first, But after three years of shooting them I am out of the clicking business.