Help scope moa problem

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by etisll40, Mar 10, 2013.

  1. etisll40

    etisll40 Well-Known Member

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    I just got a new scope and it has about 50 MOA of adjustment, not much really. I'm using it on a 308 BAR that is very accurate, with the last scope. Today I mounted the scope and it is almost against the rail. The rail is -0- MOA. I had to crank the elevation up all the way and was still 2 inches low at 100 yards. WTF, I guess I don't understand the scopes bore line and the guns bore line correctly. What should I do now? Mabe someone can explain this to me. Almost all of my rifles have a 20 MOA and scopes, 50 or more MOA. I guess I haven't shot long enough to have had to dial all the way up?

    I'm out of elevation and 2 inches low at 100. Should I be shooting backwords!? lol

    Please explain. Maybe the dial on my scopes is backwards? haha

    HELP.
     
  2. etisll40

    etisll40 Well-Known Member

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    Still looking for someone that understands bore line and scope height to scope bore line. I can't use any of the MOA on my scope at the moment as something appears wrong with the height of the rings on my scope. Other possibilities are, elevation knob was put on backwards or the manufacturers rail put on backwards and slopes the wrong way (MOA) making the MOA negative?

    Thanks
     

  3. BrentM

    BrentM Well-Known Member

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    I am no expert so who know's what you might glean from this: check the total moa of the scope and see if it is even working first. For example, set the rifle up on bench and locked down well. Look through the scope and turn the elevation dial to full up. While looking throught the scope you should see the reticle move. Now turn the elevation to full down and count the clicks, MOA, or turns until you see no more reticle movement. That is your total movement and will tell you if the scope is even working.

    If it is, then perhaps the rail is in fact on backward if it is 20 moa rail. If it is a 0 moa I don't see how it matters.

    I would guess you need a 20 MOA or even a 40 MOA rail if the scope is working correctly to be close to the center of the scopes movement or have that scope repaire or replaced. Perhaps use of your other scopes to double check?

    ??
     
  4. etisll40

    etisll40 Well-Known Member

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    Thanks Brett. I went back to the shop but those guys are like you and me, although, the rings are so low, the scope is touching the rail, possible pulled by the rings? I took it off and there is no dent, but is it possible I bent it a touch? I put a cleaning rod in the muzzle gently and then put a level on it until it was level. I had it in the vise so I then took the level and put it on the rail and it is about 3/8" higher in the front, so I'd guess that is 20 MOA? Seems correct to me, scope slanting upward?

    I'm going to try higher rings, as that's the only thing I can think of? The MOA dial moves the scope properly. I'll update this after I check it out at the range.

    Thanks
     
  5. cwinner

    cwinner Well-Known Member

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    If it is a sloped rail, the higher portion should be towards the rear with the shorter piece to the front! Take the base off and measure it with some calipers, if it has any slope at all you will be able to measure the difference, it needs to,slope forward.....this may be your issue if there is any slope to your rail.
     
  6. etisll40

    etisll40 Well-Known Member

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    I think it is the opposite, you want to add MOA, it should slope upwards.
     
  7. BrentM

    BrentM Well-Known Member

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    Cwinner is right
     
  8. cwinner

    cwinner Well-Known Member

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    It definitely needs to slope forward, what you are doing is raising the angle of the bore relative to centerline of scope.......trust me on this, I have mounted one backwards myself one time!!
     
  9. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    When shimming or using a MOA type mount you need to have the tail end up so much of your MOA(in the scope) is used pulling the rifle down to the paper at short range. I don't use 20 moa rails, but I have had to use shims on the tail end of a scope mount to get it right.
    Look at a blade sights rifle; works the same way.... Pull the back sight up higher for more barrel incline to hit on target at longer range. The thing that usually screws people up is you put the rail on and then dial it back out for short range. I'd rather pull up and leave the scope optically centered; that doesn't work much past 800 yards though with most calibers.