Moa Reticles

Discussion in 'Long Range Scopes and Other Optics' started by overbore, Jul 31, 2007.

  1. overbore

    overbore Well-Known Member

    Messages:
    308
    Joined:
    Oct 14, 2004
    I know Nightforce sells both two an one minute reticles but I have no side by side comparisons for long range estimation to verify a LRF value or to get a range on a non reflective target. Any inputs?? Many thanks, Overbore
     
  2. Mikecr

    Mikecr Well-Known Member

    Messages:
    4,264
    Joined:
    Aug 10, 2003
    If you're referring to reticles like the NP-R2 with MOA hash marks, these are for hold-off, not range estimation.
     

  3. jwp475

    jwp475 Well-Known Member

    Messages:
    2,595
    Joined:
    Feb 4, 2005


    They can also bw used for range estimation.... The fomular is as follows, target hieght in inches divided by the number of MOA time 100 equals distance, Example a target that is15" high and brackets at 2 MOA is 2 divided into 15 equals 7.5 times 100 equals 750 yards......
     
  4. Mikecr

    Mikecr Well-Known Member

    Messages:
    4,264
    Joined:
    Aug 10, 2003
    Except 15"/(2*1.047)"*100 = 716yds
    The MOA would need to be normalized to inches.
    How you gonna know 15" through a scope @ 750 anyway?

    I know when I watch woodchucks as far out as ~600yds at 25x, they look like grizzly bears!

    Sure it's possible to crudely range. But the MOA marks ARE for hold-off..
     
  5. jwp475

    jwp475 Well-Known Member

    Messages:
    2,595
    Joined:
    Feb 4, 2005


    I used a number as an example...Mill recticles have been used for ranging for a long time and MOA reticles can be as well...Many who compete in tatical matches use thier reticles for ranging as some matches do not allow range findersor have non reflective targets.. I have used my reticle (MOA) in reverse many times to find out how large a target is after ranging it with LRF... I also use MOA not IPHY yards and it works just fine for ranging that way and that is exactly how Nighforce sugest it to be used...........

    Thread here about the same subject

    http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=251878&Main=23369#Post251878
     
    Last edited: Jul 31, 2007
  6. sscoyote

    sscoyote Well-Known Member

    Messages:
    1,255
    Joined:
    Feb 26, 2003
    Absolutely, in fact the 1 MOA stadia will provide for .01 MOA interpolative ranging accuracy, and when combined with a high power scope will be one of the most accurate optical ranging devices short of a theodolite.

    Any reticle with more than one stadia point in it can be applied as a rangefinding device, sometimes with remarkable accuracy (assuming u've guessed tgt. size accurately). Better than guessing, that's for sure!!
     
  7. flims

    flims Active Member

    Messages:
    43
    Joined:
    Oct 18, 2006
    if night force says that you should divide by the amount of minutes then they must have made sure that the 1.047 value has been considered in the equation. can you test that it does not take into consideration that 1.047?
    another point, i have been thought that range finding using reticles is usally accurate to about 5% by trained people. at 700 thats +/- 35yards. some cartidges might not be effected by this error. some might.
    is the reticle in the 1st focal plain? im asking this because if it is not then the extra mag wont proof so beneficial.
     
  8. Buffalobob

    Buffalobob Writers Guild

    Messages:
    5,085
    Joined:
    Jun 12, 2001
    The early rangefinding scopes worked by the shooter changing the magnification to determine the range.
     
  9. sscoyote

    sscoyote Well-Known Member

    Messages:
    1,255
    Joined:
    Feb 26, 2003
    The finer the reticle stadia subtension and the higher the magnification the more accurate the ranging becomes. The best thing that could happen is that the g'hog looks like a bear. This way the "edges" of the game can be more easily resolved, and any adjustments in size of tgt. can be approximated better. It's not a perfect system by far, but the MOA system is more accurate than any other ranging/ballistic reticle that has a larger "subtension unit." Here's the most basic equation (modified mil-ranging formula) for any reticle (inches to yds.)--

    tgt. size (") x range of reticle subtension meaurement (usually 100 yds.) / reticle subtension measurement / quantity of gap tgt. occupies (tenths of total gap) = range (yds.)

    Here's the MOA equation for the 700 yd. g'hog--

    15 x 100 / 1.0472 / 2.0 = 716

    The subtension unit of 100/1.0472 can be simplified to make it quicker to calculate-- 95.5

    IMO, a g'hog would be one of the better tgts. to use for reticle-ranging as it tends to be less mobile than most other game. Nice to know the system has some viability if the laser doesn't work. Besides what's more rewarding than a 700 yd. g'hog that's successfully engaged with calc's rather than a laser?

    More than 1/4th of the description of the NP-R2 reticle in the NF Reticle Specifications handbook is dedicated to describing the system they use for ranging with it.

    IMO, it's important to understand the formula as noted above since it allows for reticle ranging with any reticle.
     
    Last edited: Aug 1, 2007
  10. Sendero_Man

    Sendero_Man <strong>SPONSOR</strong>

    Messages:
    1,706
    Joined:
    Feb 4, 2007

    NF scopes are 2nd focal plane. They are made to be used at the highest magnification.... ie 5.5-22x50 would be correct at 22 power. 22 Power 2 MOA on R2 reticle would double at 11 power (4 MOA) and quad. at 5.5 power 8 MOA).
     
    Last edited: Aug 1, 2007
  11. Mikecr

    Mikecr Well-Known Member

    Messages:
    4,264
    Joined:
    Aug 10, 2003
    I'll tell you what, I'd say the same if I were marketing NF scopes..
    But I believe this: MilDots are for ranging, not hold off, and MOA marks are for hold off, not ranging.

    Use of MOA ranging does sound like fun. Sure.
    But I think ANY optical ranging would degrade my shooting system(which includes LRF). I just don't think its accurate enough in the real world.

    For example;
    NF reticles are calibrated at 22x according to their reticle manual, But I use 32x NF scopes. There is no detent at the calibrated power position, so I'd be guessing 22x. That's guess#1
    In this discussion, we mention a target of 15" but it's completely crude to assume target size with any accuracy in the field.
    Thats guess#2
    We talk about the target bracketing 2moa. Not 1.9 or 2.1.
    Uh Huh..Think 22x real hard..
    Thats guess#3

    Combining the guesses, and somehow doing the math in the field, I dial in for 725yds based on a 15" chuck at 2moa -calibrated. But because I'm just not so good at this, I end up missing.
    Later, I figure out that the chuck was actually 14.75", and the true MOA was 2.1. So I was 6 clicks off shooting at a 670yd chuck, while dialed into 725yds..

    This would not have happened using my LRF, which is completely legal for use in HUNTING.
    For you guys that can do it, I salute you. I see alot of challenges there.
     
  12. sscoyote

    sscoyote Well-Known Member

    Messages:
    1,255
    Joined:
    Feb 26, 2003
    I'd have used the LRF too, assuming i didn't forget it. Sounds like u know a thing or two about reticle-ranging Mike. I still think the MOA system is better for it...IMO. U could calc the 32X subtension with the help of the laser, and making several avg. readings, then "reverse milling" on a tgt. of known dimension.

    I guess the question comes to if i have a system established that might get me that chuck, then why not try, if the laser's out of the picture for whatever the reason?? For me, and only me, a chuck is not a buck--heck the farmer doesn't care if u wounded him, and i've known a few that loved me attempting to eliminate their pests.
     
    Last edited: Aug 1, 2007
  13. jwp475

    jwp475 Well-Known Member

    Messages:
    2,595
    Joined:
    Feb 4, 2005
    Nightforce scope are calibrated as follows, 2,5X10= 10 power,3.5X15=15 power, 5.5X22=22 power,the 8X32 and the 12X42= 22 power
     
  14. overbore

    overbore Well-Known Member

    Messages:
    308
    Joined:
    Oct 14, 2004
    MOA

    ranging is also used in the Horus H-25 system which has won a significant number of sniper championships that are deliberately set up to have non-reflective targets. Great inputs, gents. Many thanks, Overbore