Quantcast
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Ranging Practice discussion thread (spoilers)

Discussion in 'Rifle Country' started by taliv, Aug 16, 2010.

Thread Status:
Not open for further replies.
  1. taliv

    taliv Moderator

    Joined:
    Oct 23, 2004
    Messages:
    22,355
    Please use this thread to discuss the ranging practice challenges. Reference the challenge by post number.

    If you need a refresher on the formulas try this link
    http://www.scribd.com/doc/2069052/Mil-and-Moa-Range-Formulas-for-different-Combinations

    And if you need basic instruction, try this software http://shooterready.com/

    --------
    Challenge in post 3
    1858, assuming your large hashes are 1mil and capt rustbeard there is 30" tall, i'd range it at 500m, but .7mil was my dope for 300 yrds (100 yrd zero)....OH, i just saw you said .7 was your windage... i misread that as your comeup

    What (shooting) range was that at?
     
  2. Maverick223

    Maverick223 Member

    Joined:
    Dec 19, 2008
    Messages:
    11,269
    Location:
    28078
    No answers?...or no guesses either?

    That doesn't work if you have THR set to shaded background. In other words I can see the answers. :(
     
  3. taliv

    taliv Moderator

    Joined:
    Oct 23, 2004
    Messages:
    22,355
    no discussion in the other thread. just pictures.

    well, close your eyes then :) edit: seriously, if you have a alternative suggestion, plmk

    are you measuring to the bottom of the wood? or the bottom of the rust to get your 600 yrd answer? (edit: you could be right.. i don't know yet)
     
  4. Maverick223

    Maverick223 Member

    Joined:
    Dec 19, 2008
    Messages:
    11,269
    Location:
    28078
    Bottom of "Cap'n Rustbeard"...assuming about 36in. target size, and doing the math in my head so I am probably off by a fair margin.

    P.S.: Would you mind adding the targets to this thread as well (less the answers)? This promises to be a fun little challenge.

    :)
     
  5. baldeagle93

    baldeagle93 Member

    Joined:
    Jan 28, 2010
    Messages:
    72
    Location:
    Memphis, TN
    I like the challenge, but would prefer the target to be captured at a good mil position.

    I got the first one, the second one is a little more tricky due to not knowing exact target size or familiarity with MOA reticle. I am going to assume that it is a typical man size target like the first. By my calculations...and I could be way off, but I got 740 yards.

    Like my teachers always wanted...I'll show my work :scrutiny:

    Known Data
    TZ = 40"
    Mils = 1.5

    40"/36"=1.11

    1.111 x 1000 = 1110

    1110 / 1.5 mils = 740 yards

    anyone agree??? :cool:
     
  6. Maverick223

    Maverick223 Member

    Joined:
    Dec 19, 2008
    Messages:
    11,269
    Location:
    28078
    I'm going to revise my answer and go with 650yds. Initially it looked to be about 1.6mils, but now I see the "top of the head" isn't flush to the hash, making it right at about 1.5mils. Still assuming a 36in. target, milling reticle, and FFP (or at the correct magnification).

    :)
     
  7. baldeagle93

    baldeagle93 Member

    Joined:
    Jan 28, 2010
    Messages:
    72
    Location:
    Memphis, TN
    So our "known" target size is the only thing separating our calculations...that's good to know.

    Does the OP know what the true distance is???

    Good to back on...works been busy (about time!) and its been too hot to shoot and since the rim fire challenge distance changed I can't take advantage of the indoor range :( Now it's too hot to shoot and too hot to enjoy my other hobby, riding my motorcycle!
     
  8. LemmyCaution

    LemmyCaution Member

    Joined:
    Jun 4, 2008
    Messages:
    890
    Regarding post 2:

    Assumptions:

    1: Mil Dot reticle
    2: 1 meter high target
    3: FFP reticle or set at proper magnification

    Estimation:

    Height of target is 1.1mil

    Answer:

    Range is 909 meters.
     
  9. LemmyCaution

    LemmyCaution Member

    Joined:
    Jun 4, 2008
    Messages:
    890
    Regarding post 3:

    Assumptions:

    1: 1mil between major stadia lines
    2: 1 meter target height
    3: FFP reticle or set at proper magnification

    Estimation:

    Height of target is 1.5mil

    Answer:

    Range is 667 meters.
     
  10. Maverick223

    Maverick223 Member

    Joined:
    Dec 19, 2008
    Messages:
    11,269
    Location:
    28078
    Yep, pretty much...along with the fact that I was too lazy to get a pen and paper so I did the math in my head and rounded a few things (negligible IMO because there wasn't sufficient significant figures from the guestimation of target size to make a worthwhile difference).

    :)
     
  11. taliv

    taliv Moderator

    Joined:
    Oct 23, 2004
    Messages:
    22,355
    this is going to be even more entertaining than i first imagined :evil:

    I'm going to go take a bunch of pictures this week of non-standard-sized-targets.
     
  12. Maverick223

    Maverick223 Member

    Joined:
    Dec 19, 2008
    Messages:
    11,269
    Location:
    28078
    Evil, you are! stir.gif At least give us something (a car, tree, person, et cetera) for scale.

    :)
     
  13. baldeagle93

    baldeagle93 Member

    Joined:
    Jan 28, 2010
    Messages:
    72
    Location:
    Memphis, TN
    Then make sure that you have something identifiable in the picture to determine...oops, guess Mav beat me to it!

     
  14. Tim the student

    Tim the student Member

    Joined:
    Feb 1, 2009
    Messages:
    3,427
    Location:
    IA
    Cool thread here!
     
  15. MCMXI

    MCMXI Member

    Joined:
    Jul 1, 2008
    Messages:
    7,499
    Location:
    NW Montana
    EDIT: Images moved to sticky thread HERE

    I measured myself and I'm right around 40" from crotch to crown so the rusty steel targets shown could be considered representative of a 6' male.

    :)
     
    Last edited: Aug 17, 2010
  16. blackops

    blackops Member

    Joined:
    Jun 6, 2009
    Messages:
    1,238
    post 4 first pic, 660yds.
     
  17. MCMXI

    MCMXI Member

    Joined:
    Jul 1, 2008
    Messages:
    7,499
    Location:
    NW Montana
    In this case, if you were aiming at the center of mass using a typical .308 Win and estimated the target to be at 660 yards, you would have missed the target (center of mass) by something like 50" or just over 4'. That's not even taking into account the wind call. As one instructor told me, every miss educates your opponent!

    Added in edit: I've missed lots of targets even when I knew the range to within a few feet so I'm definitely not trying to be a wisea$$. I'm just making the point that without a laser range finder, range estimation can be very difficult, particulary when you have to estimate the size of the target. Under these conditions, we can miss by A LOT!!

    :)
     
    Last edited: Aug 17, 2010
  18. taliv

    taliv Moderator

    Joined:
    Oct 23, 2004
    Messages:
    22,355
    really? cause it looks exactly the same, just at a different magnification

    i guessed 333 yrds on the guy in the middle in the back on pic #2 in post 4
    and 277 yrds on guy on the right in pic #3
     
  19. MCMXI

    MCMXI Member

    Joined:
    Jul 1, 2008
    Messages:
    7,499
    Location:
    NW Montana
    The two targets in question are at similar ranges but seperated by something like 12" of bullet drop which may or may not make a difference. This is based on range data using my Swarovski Laser Guide. I'm going to head out to the range this week to try to get some better photos and look for other interesting targets.


    Did you assume a "typical" head size and then estimate the total height of the target?

    :)
     
    Last edited: Aug 17, 2010
  20. baldeagle93

    baldeagle93 Member

    Joined:
    Jan 28, 2010
    Messages:
    72
    Location:
    Memphis, TN
    Target size-Head = 12" (probably more like 10" which will make my yardages about just under 17% high :banghead: ...oh well, here goes nothing!)

    Target #1 (which is actually third picture)

    Tz= 12"/36" = .333
    .333 x 1000 = 333
    333/1.5 mils = 741 yards

    Target #2 (picture #4)

    Charlie on the left
    Tz= 12"/36" = .333
    .333 x 1000 = 333
    333/1 mils = 333 yards

    Charlie in the center
    Tz= 12"/36" = .333
    .333 x 1000 = 333
    333/.7 mils = 475 yards

    Charlie on the right
    Tz= 12"/36" = .333
    .333 x 1000 = 333
    333/1.8 mils = 416yards

    Charlie on the right bottom
    Tz= 12"/36" = .333
    .333 x 1000 = 333
    333/1.3 mils = 256 yards

    Target #3 (picture #5)

    Tz= 12"/36" = .333
    .333 x 1000 = 333
    333/.8 mils = 416yards
     
  21. taliv

    taliv Moderator

    Joined:
    Oct 23, 2004
    Messages:
    22,355
    Yeah I guessed typical head was six inches and measured ear to ear not by the hat

    edit: i didn't use the head to measure the body and then range on the body, if that's whta you're asking, since i assumed the mounds in front were variable heights
     
  22. LemmyCaution

    LemmyCaution Member

    Joined:
    Jun 4, 2008
    Messages:
    890
    Post 4, No.1:

    Man sized target is 0.5 meters across the shoulders. I estimate 0.7mil across the shoulders.

    (0.5/0.7)1000=714 meters.

    Post 4, No.2

    Head of man sized target is 0.25 meters high. We'll scale it by 0.9, given your admission that the targets are not full scale. I estimate 0.7mil as the head height.

    (0.25(0.9)/0.7)1000=321 meters.

    Post 4, No.3

    Ranging off upper body this time. Same 90% scale factor. I estimate 2.5mils crotch to top of head.

    (1(0.9)/2.5)1000= 360 meters.

    I see from the hidden answer that it's actually 275 meters. I can't make that work, no matter how I estimate it.

    So I start over, ranging the head this time.

    The head looks to be 0.8mil.

    (0.25(0.9)/0.8)1000= 281 meters. Close enough for anti-government work.
     
    Last edited: Aug 17, 2010
  23. blackops

    blackops Member

    Joined:
    Jun 6, 2009
    Messages:
    1,238
    1858, i was taking a 308 with a 2 moa spread in your reticle (which would equal 6 moa) with a 40" target (typical size of a human torso) Maybe I missed a few things since Ipicked up this thread from my phone, but knowing the reticle measurments for your PR would make things much easier.
     
  24. LemmyCaution

    LemmyCaution Member

    Joined:
    Jun 4, 2008
    Messages:
    890
    Blackops-

    All the reticles in the exercises thus far are based on angular mil, not MOA. The major hash marks in 1858's reticle are 1mil apart. The minor hash marks are 0.5mil.

    1mil = ~3.44 MOA.
     
  25. blackops

    blackops Member

    Joined:
    Jun 6, 2009
    Messages:
    1,238
    Lemmy, 10-4. I knew I was missing something there. Easy to overlook things from the cell. I was like, no way I would be off by 4 ft. No wonder were playing with mils. I like MOA better myself.
     
Thread Status:
Not open for further replies.

Share This Page