20 MOA rail, & hold over reticle trouble

Discussion in 'Equipment Discussions' started by winmag, Aug 22, 2013.

  1. winmag

    winmag Well-Known Member

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    Ok so I have a Leupold VX-3 Tactical 4.5-14x40 A/O. 1" tube.
    I had Leupold install the Boone & Crocket Varmint Hunters reticle at the custom shop, after checking the sub tension specs, & finding that they were almost identical to my 300WSM launching 180 Accubonds for drops.


    Leupold 20 MOA RAIL &
    Leupold PRW Medium rings

    Put it all together when I got my rifle, scope, rings etc back from CeraKote guy in time to shoot a quick 200 yd zero.
    TERRIBLE IDEA!
    My stadia lines are so far off its not even funny.

    Zeroed at 200 went bear hunting, & figured I'd field verify my drops by going long. At 600 I was like 8 feet high with my 550 yd stadia line!

    So, shot a rock at 300 with my 300 yd pin, to find out that I was about 30" low!
    So, to salvage my hunt, I zeroed my 300 yd pin @300. My 400 yd pin shoots 5-1/2" low at 500! (My 500yd pin is way over my steel target @ 500)

    So this hunt is limited to 500 & less, but I'd like to get this issue resolved BEFORE Elk season.
    Just a WAG, but I'm thinking the 20 MOA Rail & hold over lines aren't compatible(?)

    My initial solutions:
    I'm thinking either I keep the 20 MOA Rail, & dial only, & have Leupold replace the Varmint Hunters Reticle, with a set of fine crosshairs, OR replacing the 20 MOA Rail with a 0 MOA Rail, & live with not having enough "come up's" to get to any fun distance.
    Problem is I want both stadia lines for the quick & close 0-600 yd stuff, & dial past that.
    Any thoughts?
     
  2. Bullet bumper

    Bullet bumper Well-Known Member

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    With the 300 WSM and 180 grain bullet @2950 fps, the B&C reticule is designed for a 200 yard zero.
    So as long as you could get down to a 200 yard zero which it seems you did , even with the added 20 MOA rail , it should be accurate when zeroed at 200 .
    I sounds to me like they may have fitted the wrong reticule or your actual trajectory is different to what they think it should be .
    Never been a fan of BDC reticules . I like Mil dot and Mil Hash mark reticules and work out your own amount of holdovers.
     

  3. winmag

    winmag Well-Known Member

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    300WSM, 180's at tic over 3100fps.

    I really like the BDC reticle a for the close (0-600) stuff. They are quick & simple, & save time dialing, & at that close your not gonna be off by much. I still work out my actual drops before I'm satisfied with my stadia lines, & dial the rest.

    Initially I hoped to have the capability to do both. I figured a 200 yd zero was a 200 yd zero, & the stadia lines would stay the same with or without the 20 MOA RAIL.
    Now I'm just confused....
    Archery starts tomorrow, so I may just go poke a bear instead. I'll call Leupold when I get home from my hunt.
    Thanks for the reply
     
  4. Bullet bumper

    Bullet bumper Well-Known Member

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    I think that may be the problem . I am sure I read some place that the reticule for 300 WSM is designed for 180 grain bullet @ 2950fps in group A and zero @ 200 yards for group A
    They give a drop accuracy variation of 35 to 45 inch @ 500 yards across all the cartridges in group A so that's not very accurate 10 inch variation at 500 and why I don't like them much. Some will be lucky and it very close to their trajectory and others will not be.
    I found it http://www.leupold.com/wp-content/uploads/2012/07/BAS_Inst_Manual_17July12.pdf

    Your right the 20 MOA should make no difference if you can zero at 200 yards .
    If you have MOA turrets on the scope send it back and ask for a replacement MOA dot reticule and then just learn your holdovers in MOA .
    That way if you change bullets or powder loads at any point you can adjust your holdovers accordingly .
     
  5. winmag

    winmag Well-Known Member

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    Guessing you we're looking at the wrong chart.
    Here is Leupolds sub tensions / aiming system catalog that I have.
    In print (MOA) is theirs.
    In ink is mine (also in MOA)
    * 1/2 MOA is the most I'm off..... image.jpg
     
  6. Bullet bumper

    Bullet bumper Well-Known Member

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    I might be looking at the wrong one , but you said Boone and Crocket reticule .

    The info I saw said Boone and Crocket reticule not Leupold Hunter ?
    It appears now that your error is not as much as you first posted so that seems better .
    From what I can see it's only approx. 1 MOA out at 500 .
    I think that is probably the limitations of this kind of trajectory averaging type system.
    I notice you live not far from where my mother was born Hood River .
     
  7. winmag

    winmag Well-Known Member

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    I apologize. I did say Boone & Crocket Varmint Hunters Reticle, not just Varmint Hunters reticle.

    Yes my poi vs poa is as bad as I originally stated with the current setup.

    The ink pen in the picture is what I should actually be, which is right in line with the sub tensions of this reticle.

    So in short I'm super confused, & lousy at grammar.:D
    Sorry Bb:) my bad
     
  8. Browninglover1

    Browninglover1 Well-Known Member

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    Were you on the correct power? If you were on a lower power it would definitely throw your shots off, however I have no idea how your shots are dropping 30" from 200 to 300 yards. Also, have you checked the subtensions at 100 yards against a grid to verify they are accurate? Leupold could have installed it and not calibrated it correctly.
     
  9. Bullet bumper

    Bullet bumper Well-Known Member

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    You have to set your power ring on the big triangle . That would be a group A cartridge I think as the 300 WM is the only one close in group A .
    300 WSM don't appear in the list at all.
    Try that.
    Another thing is that if you are long sighted and you need to have the ocular focus right back then that will throw off the magnification ring values . As with the focus right back the scope will have greater magnification .
    If that is the case , as this reticule systems accuracy is based on the image magnification being right you may have to have the power ring on a different magnification than the instructions say . Try different settings around the big triangle setting an see what power setting gives correct hold overs . Then mark the ring with some white paint or something like that .
    In future buy a First Focal Plane scope with either a Moa or mil dot reticule . You work out your own trajectory data in MOA or Mils using a ballistic program like JBM or sight it in and shoot at targets at different ranges and discover the drops . Then you can apply the holdovers required at any range on any power .
    For level fire and no wind and ignoring altitude and atmospheric . You can just have a list stuck to your stock with each hold over at each range in MOA or Mils .
    Get out your laser range finder range the target. Look up your list for that range and you have the hold over .
    Count down the reticle subtensions that amount and that's the POI .
    It works for every cartridge because you work out the trajectory of your cartridge .
     
  10. winmag

    winmag Well-Known Member

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    I took my load info, & put it thru JBM to check my drops in MOA against the reticle sub tensions. They are so close it's not funny.

    I used this same scope on my 300Wby launching 180's at 3085 FPS & it worked great. Should be absolute minimal difference between that & my 300WSM launching 180's at just over 3100 FPS.

    Yes I used the correct magnification, (big triangle) & correct A/O setting. I even double checked.
    Ill call Leupold & talk to someone there, & report back here with my findings.
     
  11. Bullet bumper

    Bullet bumper Well-Known Member

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    I was not talking about AO settings they will only change the range focus to set parallax correction .
    I was talking about the OCULAR eye focus at the back of the scope. If you have long sightedness (Presbyopia) and this ocular adjustment is way back then the power setting marks will be wrong .
    Maybe the error was right for the 300 WBY but not the 300 WSM.
    I think you have to forget about other guns and cartridges and play with different magnification settings to make it work with the 300 WSM .
    Another thing is , you are not shooting with see through lens caps or eye glasses are you as adding another lens of anykind can distort the image .
     
  12. Browninglover1

    Browninglover1 Well-Known Member

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    My biggest concern is still that you're 30 inches low at 300. That shouldn't happen even if you used your 200 yard pin. Almost makes me wonder if something is loose in your scope.