BDC Turret knobs

Discussion in 'Long Range Scopes and Other Optics' started by Jody, May 17, 2006.

  1. Jody

    Jody Member

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    I have always been a holdover type of guy when it comes to shooting longer ranges. I read so much info on here about all of you guys using the mill-dot and the ranging recticles such as the NPR2. It seems that everybody on here is a 'click and shoot' type, and that holdovers are for newbies. Why is it that more people are not using the BDC turrets? It seems that it would be so much easier and simpler. I would appreciate anybody out there filling me in on what I'm missing. I plan on always having my rangefinder with me, so estimating yardage isn't a concern. So, if I set this scope up for my one caliber /one bullet/one speed with a simple recticle, what are the disadvantages to using a BDC turret? Why aren't more people using this setup for long range hunting? I really appreciate any information you can provide.
     
  2. Bart B

    Bart B Well-Known Member

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    [ QUOTE ]
    ... what are the disadvantages to using a BDC turret? Why aren't more people using this setup for long range hunting?

    [/ QUOTE ]They only work well when set up for one load's actual fired bullet trajectory at one altitude and atmospheric condition. Change anything and the BDC is no longer accurate.
     

  3. royinidaho

    royinidaho Writers Guild

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    Jody,

    Good comment/question.

    I don't think you're missing anything, at least no more than I am.

    I'm a hold over fella also. Mostly because I'm a "hold over" from the old days when I had a duplex reticle and figured the drop at distances from the reticle center to the top of the bottom post. Missed a lot of nice bucks that way. /ubbthreads/images/graemlins/crazy.gif

    Since I've become serious with LRH/S /ubbthreads/images/graemlins/grin.gif the next logical progression was the Mil-Dot which works pretty darn good (sux for ranging w/my eyes but great for hold over. I also use a LRF). The short coming for me is the lack of precision when attempting to discern tenths of a mil. 1/2 mil is straight forward, 6 and 7 tenths is a bit more difficult. .1 and .9 are easy, they are the bottom and top of the round mil dot respectively.

    The desire then becomes the NP-8, TMR or NPR2 which is the next level of precision.

    Regarding clicking, I realize that it is much more precise than any of the reticles but when there's hair in the field of view, my mind can't seem to keep track of how much to click where and "Damn, did I reset from the last time I adjusted" /ubbthreads/images/graemlins/crazy.gif /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/blush.gif

    RE: the BDC, none of them are designed for the bullet/velocity that I shoot thus the yardages on the reticle don't coinside with the actual distances. Just another thing to keep track of.

    My solution to the whole problem is get a cartridge that will push the bullet so that with a 100yd zero the bullet drops no more than 5 Mils at 1K. (Sweet!!!)

    My scopes can be clicked and I guess as somewhat of a newbie myself I'll practice on "rocks" and chucks but for meat for the table I'll stick w/hold over for the time being.
     
  4. jwp475

    jwp475 Well-Known Member

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    [ QUOTE ]
    [ QUOTE ]
    ... what are the disadvantages to using a BDC turret? Why aren't more people using this setup for long range hunting?

    [/ QUOTE ]They only work well when set up for one load's actual fired bullet trajectory at one altitude and atmospheric condition. Change anything and the BDC is no longer accurate.

    [/ QUOTE ]

    This is the weakness of the system.Take my 300 win sighted in at 255 the correction needed at 650 yards and sea level altitude is 67.7". the same load at 7000" elevation needs 59.9" of correction a difference of 7.8". the farther out the wider the dfference
     
  5. Ridge Runner

    Ridge Runner Well-Known Member

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    just by playing with a ballistics program, I found that a 4" change in the bar pressure will cause you to miss the proverbial "broadside of a barn" at 1500 yds. I'm talking a change in POI of over 100". BDC's do not take atmosperic changes into consideration.The BDC's if you do your homework before having it made work well to about 700 yds, beyond this the everchanging weather conditions have to much effect on POI.
    JS
     
  6. bsb

    bsb Well-Known Member

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    I make my own on excel, its a Piece of paper wrapped around turrent with clear tape looks good! you would be surprised) and good for 1500 yrds on the rum. I Put on a new one if I am going to hunt at see level or 8000 feet no games.
    maybe I can put a picture on here later.
     
  7. Jody

    Jody Member

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    Thanks to everyone for the information.
     
  8. longgunshooter

    longgunshooter Well-Known Member

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    [ QUOTE ]
    I make my own on excel, its a Piece of paper wrapped around turrent with clear tape looks good! you would be surprised) and good for 1500 yrds on the rum. I Put on a new one if I am going to hunt at see level or 8000 feet no games.
    maybe I can put a picture on here later.

    [/ QUOTE ]

    got a pic...?

    im very interested in doing this.

    Thanks.
     
  9. HoytemanPA

    HoytemanPA Well-Known Member

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    I don't know if this is similar to what roygeterdone is talking about but here is a pic of mine. This was from my first attempt, using a lookup to populate the major marks to the nearest yardage by a multiple of ten. I have since changed it to 5 yard increments out to 2500 and then it goes back and selects the yardages to print on top of the moa marks. I limit lines of numbers to 2 (29 moa),but it could be reformatted for 3 (44 moa)but things get quite small. 0 to 15 right and left windage stickers shown... I always got screwed up with the windage numbers. Now I can keep it straight, out to 14moa wind anyway.

    I'm working on one that you can manually enter drop charts calculated elsewhere and it populates the stickers, it currently only works for Leupolds. Spacing in Excel is column width .33 per 1/4 click if anyone wants to mess with it.


    [​IMG]
     
  10. 4ked Horn

    4ked Horn Writers Guild

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    This thread may be interesting to those following this subject. Most folks here probably have seen it. Scroll way down for some pictures of the turret wraps that emailed to everyone. Somewhere in that thread is the web address of a company that will make custom aluminum bdc turrets if I remember right.
     
  11. magicofmt

    magicofmt Well-Known Member

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    HoytemanPA
    Tried to send you a PM, your email isn't working. Could you send me the spreadsheets you have made up, it will save me tons of time trying to figure out marks and spacing.
    Appreciate your time.
     
  12. timberflint

    timberflint Member

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    4ked Horn

    Thanks again for your turret wrap spead sheet last year. Have them on at least 5 scopes and have adapted it to some other than Leupolds.

    Works great for me. Excellent in the prarie dog towns. Only problem was getting my rifles back from my buds once they figured it out. They shot up all my ammo. Headed to South Dakota in a couple weeks and plan on also makiing one up for windage on both my 22/250 and .223.

    Best to you.

    tim wolf
     
  13. robbor

    robbor Well-Known Member

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    4kedhorn, if you have the program for the BDC yardage stickers, would you mind sending it to me. I was just looking at BDC knobs and they were pretty expensive from leupold.
    With the BDC stickers what indicator do you have to tell what revolution you are on??? I had thought previously (because I have a silver LR) of getting another turret cover and cutting it down on the lathe to get rid of the black threads and protect them and then re anodize or paint the adjustment itself silver so everything matches. I just hate seeing a black knob sticking out on a silver scope. I would think if the yardages were made very short they could dissapear below the cover and I would just have to put a mark on the cover.
     
  14. Buffalobob

    Buffalobob Writers Guild

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    If you don't get a reply from 4kd horn. Send me an email and I will forward his turret wrap and Browns Dog's to you. I have them both. One is in Excel and the other in MS Word