sighting in with a 20 MOA mount

Discussion in 'The Basics, Starting Out' started by cheytownshaun, Jun 16, 2011.

  1. cheytownshaun

    cheytownshaun Member

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    Hi all i'm looking for some advice on sighting in my 300 Win Mag w/ a 20 MOA mount for LR shooting. I've never used one so my question is do i need to set a point to aim at high on target frame and expect the bullet to hit way low at 50 yards for first sight in or do i have that backwords?gun)
     
  2. venom600

    venom600 Well-Known Member

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    Jan 25, 2011
    Quickest way is to bore sight your rifle first....that'll get it in the right ball park. You can even do this w/o the use of a tool by removing your bolt and looking down the bore to see if it is aimed at your 50 yd target, hold it there and then adjust the reticle to be on the bull. That'll get you pretty darned close and you can adjust from there.

    --Ben
     

  3. rcdinaz

    rcdinaz Well-Known Member

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    Feb 22, 2011
    Yes, bore sight it. My 300RUM had almost no change to start with, maybe just lucky but at 50 yds starting it shouldnt take a lot of cranking.
     
  4. Ridge Runner

    Ridge Runner Well-Known Member

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    use quality rings, mechanicly center the erector tube, then dial it down 20 moa, you'll be on paper at 50 yards, thats how I do it.
    RR
     
  5. rscott5028

    rscott5028 Well-Known Member

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    You will sight it in exactly like you've always done with regular bases and rings. You want to aim at the bulleseye and hit dead on at 100 or 200 yds depending on your preference.

    With regular 0 MOA bases, half of your adjustment range is above center and half is below. But, you never dial to shoot below your target. So, half of your adjustment range is wasted.

    The only difference with 20 MOA bases is that the downwards slope of the base will give you an extra 20 MOA worth of upwards elevation to play with when you dial the turrets for long range.

    In order to gain 20 MOA of upwards adjustability, you lose 20 MOA of downward adjustment range, but who cares. Like I said before, you never aim that far low.

    -- richard
     
  6. KurtPiet

    KurtPiet Active Member

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    Mar 15, 2010
    I have 20 MOA bases on all my rifles and have gained in some cases as much as 35 MOA's. How?? I shim the rear of the base enough to have just enough that when I come back to zero I can go past and then come back up to my zero. This way I am always working on the same side of the nut. Beside it has been my case that when and if you have to dial down to 50 yards you usually have to dial up anywhere from 3 to 4 MOA's. This is usually the same amount of MOA's to get you to 200 yds.
     
  7. rscott5028

    rscott5028 Well-Known Member

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    It sounds like you have it figured out. But so that others understand, you wouldn't want to place the scope or base in any kind of bind. So, shimming would need to be done correctly and with proper bedding.

    Otherwise, you can just buy a 35 MOA base if that's what you really need for the distances/cartridges you intend to shoot.

    -- richard
     
  8. cheytownshaun

    cheytownshaun Member

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    Thanks all, for your help w/ the 20 MOA mount sight in rscott5028 info was great and really helpped me to understand what was going on there and with all the info i was on paper at 100yrds with 1st shot and hit the 9 ring on target. The 50 yrd range was in use so had to use 100 yrd range. thanks again:)
     
  9. KurtPiet

    KurtPiet Active Member

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    I use one piece bases so as to not put the scope in a bind. When I started out doing this customers would bring my scopes that had 25 , 30, 35 Mao's total well that isn't enough for a 1000 and the big guns well just weren't around here. So if like most small town someone had a scope with 35 Mao's that was a high dollar one back then. Doesn't sound like much and yea they could of saved for something better but when you got 10 buck and 9 go for everything that dollar that left was for bullets not scope that cost 5 and 6 hundred dollars they were for rich folks. Now a days thats the standard.