30 moa or 40 moa base for new build?

Discussion in 'Long Range Hunting & Shooting' started by jskmtd, Apr 22, 2013.

  1. jskmtd

    jskmtd Well-Known Member

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    I'm putting together a new 300 win mag and I'm not sure which base to use. The question I have is, how close to the bottom of a scopes travel is OK? With the 30 moa base I should have around 17 moa after zero, and with the 40 moa base I will have about 7 moa left after zero. I want to get the most travel out of the scope, but not sure if being cranked down that low all the time will damage the scope?
    Thanks Jon
     

  2. Broz

    Broz Well-Known Member

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    I take it your scope has close to 100 total moa? If you want all you can get go with the 40. Just refrain from bottoming the turret out or at least do it gently.

    With the 40 you should have close to 90 moa up. That would get my 300 win out to past 2200 yards. Is this what you are looking for?

    Jeff
     

  3. jskmtd

    jskmtd Well-Known Member

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    Yes that is what I'm looking for Jeff. I just wasn't sure if it would damage the scope to be that close to bottoming.
    Thanks
    Jon
     
  4. Broz

    Broz Well-Known Member

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    you going to use the 215 or the 230's ...:D gun)
     
  5. jskmtd

    jskmtd Well-Known Member

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    I'm thinking the 215's, but I have some of each. I just wish my barrel and stock would get here. Hopefully in the next month or 2.
    Jon
     
  6. azsugarbear

    azsugarbear Well-Known Member

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    A lot of the answer centers around the quality of scope that you have. As a general rule, the more you spend on glass, the better the quality and performance. Keep in mind, that when I use the terms quality and performance, I am not talking about glass/lenses, but rather the durability and repeatability of the turrets.

    Scopes that are not "top shelf" tend to have more issues when they get close to bottoming out. They are not always precise and may not always return you to your zero.

    When zeroing your scope with 100 MOA of total travel, you cannot assume that your 200 yd zero will be right in the pre-set center of the scope with 50 MOA travel up or down. More likely than not, you may find you only have 45 MOA before bottoming out. Having a 40 MOA rail will force you to do precision work at the very bottom of your turrets adjustment ability. Is the quality of your scope up to that?

    A good exercise would be to run a ballistics chart for your 300 Win mag load to see how much further out a 40 MOA rail will get you over a 30 MOA rail. I have no horse in this race and am just too lazy to do it myself. But I bet, the additional 10 MOA will only buy you another 150-200 yds of distance. Let me know if it turns out different.
     
  7. jskmtd

    jskmtd Well-Known Member

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    The scope is a 6.5-20x50 lr with target turrets. Looking at shooter the additional 10 moa is only 130 yards. I have several of these scopes and used one that is on a 20 moa rail to figure what I would have left before bottoming out. The 30 moa rail would get me somewhere close to 1950 yards which is farther than my current rangefinder will range. If I get the 40 moa rail that will give me an excuse to upgrade my rangefinder.:D
    Jon
     
  8. sp6x6

    sp6x6 Well-Known Member

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    Plus you can crack rocks at that range but you will have no Energy or speed left
     
  9. WildRose

    WildRose Well-Known Member

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    Just be honest with yourself about how far you are going to be shooting and the question pretty well answers itself.