Ok, just joined with a question.

Discussion in 'General Discussion' started by BamaBrad, Apr 19, 2015.

  1. BamaBrad

    BamaBrad New Member

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    Apr 19, 2015
    I hope you can help me out. I have a 270 that I have zeroed in at 100 yards. I have a Vortex Viper 3x9x40 on it. It came with a sticker so I can mark different ranges on the sticker and compare them to my scope. This is only out to 400 yards. My scope is moa and in 1/4 clicks. I for some reason am having the hhardest time to try and figure out the formula for dividing the target size by the yards times the length or whatever the formula is. I understand that it is not actually an inch at 100 yards also. Can someone help me with the simplest way of getting on target out to 400-500 yards with the supplied information and tell me what information I need to put on my sticker to mount to my scope? I would much appreciate it. Here is attached screenshoots of the bullets I am using.
     

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  2. FearNoWind

    FearNoWind Well-Known Member

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    Not sure what the reticle image is supposed to represent but the ballistics dope sheet does not reflect a 100 yard zero. A 100 yard zero should reflect "0" rather than -4.39 inches (roughly 4 MOA) . The other thing about the chart that troubles me is that it is not progressive. A verticle correction over distance should be somewhat linear - this one has a downward spike at 300 yards.
    Can you post information on what bullet you're using (brand, caliber, style, etc.) and muzzle velocity information? That'd help a great deal.
     
  3. HARPERC

    HARPERC Well-Known Member

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    When I get the lower picture big enough to read it's giving you a maximum point blank.
    If your rifle is sighted in at 339 yards, your bullet impact will neither be more than 4.4" above or below out to 388 yards. The theory being if all inputs are correct, then in the field you can make a center hold and still be in the vitals of any critter whose vitals tape 8.8"

    If you zero at 100 yards the numbers don't work.

    I think that's what you're asking, and what I'm seeing? LOL!
     
  4. BamaBrad

    BamaBrad New Member

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    Apr 19, 2015
    I will get the bullet information. I am new to the program. I have two. Sterlok+ and Exterior Ballistics. I am wanting my rifle on at a 100 yards but still be able to hit out to 400 yards, or I have read about having a point blank range. I don't know which would be better. I would appreciate any help. Thanks.
     

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  5. BamaBrad

    BamaBrad New Member

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    Ok, I promise I understood this month's ago and now I can't. I have joined in hopes thag I can habe some folks shed some light on me. I have a Ruger 270 and am shooting a Barnes .277 diameter bullet /ttsx bt. Bullet length- 1.322 - Sectional Density 0.242 - BC 0.392.

    I have plugged in my information in my apps (Sterlok+ & Exterior Ballistics) and here is the results I have for point blank range. 381 yards. It tells me recommend zero is 332.0 yards and the trajectory height is 4.4 inches at 100 yards??? I don't understand what that means. Do I need to adjust my scope 1/4 inches x 4.4 to be dead kn at 381 yards.

    I am wanting my rifle with this load sighted in at 100 yards and have a 6 inch vital zone (such as a deer) that if he walked out to 300 I could hold on him and still be in my mpbr.

    Here is the card and reticle it provided me for the information I put in. Can anyone in lighten me on what I am doing wrong or making this harder thank it is please, and explain what the card is telling me. I am a pistol shooter and want to learn about shooting rifles at mid range distances. Thanks.
     

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  6. FearNoWind

    FearNoWind Well-Known Member

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    It's a struggle, but let's see if this can help.
    First of all, I don't understand why you're asking your computer program to give you results in 15 yard steps and why (if you want data out to 400 yards) you llimit the request output report to 300 yards.
    Based on what you've done thus far, if you zero your rifle (adjust the scope to hit the center of a target) at 332 yards, your shot will be about 4 1/2 inches high at 100 yards (well within the kill zone for most big game) and still within the MBPR zone at 381 yards.
    Your image indicates that, based on the data you entered, your point blank range (the distance at which you should be able to achieve a strike in the kill zone on your game) is 381 yards. MPBR (maximum point blank range)is essentially the distance at which, based upon the ballistics information you've calculated, you should be able to place a shot within a given size circle without making adjustments in the scope or relying on "hold over".
    I'd suggest you read this:
    http://www.chuckhawks.com/mpbr_hunting.htm
     
  7. HARPERC

    HARPERC Well-Known Member

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    I may not have your question firmly in my head, but I think you should skip MPBR, and instead plug in a 400 yard zero, along with your other inputs, and it should give you the numbers for ranges up to that.

    If your program doesn't allow it use the G7 calculator at the top of the page,
     
  8. jreppert

    jreppert Member

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    Feb 23, 2015
    You didnt mention anything about determining your muzzel velocity, did you chronograph the load?