Ian, I need your help, please?

Discussion in 'Equipment Discussions' started by Warren Barrett, Oct 5, 2004.

  1. Warren Barrett

    Warren Barrett Well-Known Member

    Messages:
    106
    Joined:
    Mar 10, 2002
    Hello Ian or any one else experienced in this area.
    In need of a devise to give the correct angle of shot from a level position to be able to take to the Rockies and be spot on.
    Also in need of some percentages and or formulas to figure with the info. the devise gives to subtract from my initial MOA come-ups for the different yardages.
    Leaving on the 12th of this month, so don`t have much time to get myself prepared.
    Did my question make sense or clear as mud? I`ve seen where some of you have covered some of this if not all in times past, but can`t remember really that much about it.
    thanks in advance, Warren
     
  2. Pete Lincoln

    Pete Lincoln Well-Known Member

    Messages:
    658
    Joined:
    Mar 17, 2004
    Warren, you need an Angle Cosine Indicator. a few places have them, badger Ord has em and a mount.
    Pete
     

  3. Warren Barrett

    Warren Barrett Well-Known Member

    Messages:
    106
    Joined:
    Mar 10, 2002
    Pete, is the ACI unit accurate out to 1500yds?
    Thanks for responding, Warren
     
  4. Ian M

    Ian M Well-Known Member

    Messages:
    2,410
    Joined:
    May 3, 2001
  5. Guest

    Guest Guest

    Warren Barret-- There is a great post about shooting at inclination angles at the below link.
    http://artactical.com/eve/ubb.x?a=tpc&s=692600194&f=701602405&m=859609536

    The angle cosin indicator does not work at long range and has no chance of getting you the correct answer at 1500 yards.

    The guy at snipertools.com claimed in the thread on A.R. Tactical that special forces use his product. I can tell you that I was just at Fort Polk, Louisiana, where the Joint Readiness Training Center is located (JRTC) and not one single sniper involved in the training from 5th Group or Delta had a Angle Cosin Indicator on their rifle or in their gear. I asked every sniper there that we worked with if they had one, or used one. None of the Urban snipers at Shugart Gordon Center used them either. If you want to learn the right way to shoot at angles learn it from a Pro who can teach it and do it. The method S1 uses works at Ultra Long range, and it is the method the guys that do it for a living use.

    I know the moderators get aggravated when guys tell the truth, but try both methods past 800 yards, and you will see who is telling the truth. The ACI is a gadget and the method that proposed with it does not work in the world of long range shooting. Anyone who has actually tried it knows it produces the wrong answer.
     
  6. danacobb

    danacobb Well-Known Member

    Messages:
    57
    Joined:
    Oct 21, 2003
    The cosine indicator would work good with an accurate printed agnle compensation (as in the one Exbal produces with Excel) chart if it showed you the angle instead of the angle indicator. Does anyone know if there is something like this that shows the agnle. If not, how do you accurately (and quickly) determine your anlge?
     
  7. Dave King

    Dave King Well-Known Member

    Messages:
    2,362
    Joined:
    May 3, 2001
    Antslayer is correct in that there are several methods of "doing" inclined fire. Here's an article that's pretty good and explains some models very well.
    http://www.exteriorballistics.com/ebexplained/article1.html

    What it pretty much boils down to is how large is your target area (kill zone), what is the distance (shorter is more forgiving) and what is the angle (less is more forgiving). If you're talking rather short distances and a large target area (many inches) and moderate angles (NOT 90 degrees for sure) you be fine with the old(er) but tried and true COS(Angle) * base/gravity distance version (the ACI type model). If you're talking precision fire onto a small target at longggg range the more accurate methods could be better.

    IMHO for hunting purposes using the ACI or MilDot Master device and their COS(angle)* base distance is good enough and to use the the other "more correct/accurate" models amounts to just buffing a turd, the critter will be dead in all cases.
     
  8. Guest

    Guest Guest

    Dave King--

    "to use the the other "more correct/accurate" models amounts to just buffing a turd, the critter will be dead in all cases."

    In the example on A.R. Tactical the "more correct/accurate" model shows that there is over 2MOA (OVER 19 INCHES) of VERTICAL ERROR when using the ACI.

    This is for a shot at 40 degrees and only 800 yards, very common in mountainous terrain.

    Mr. King that is not "buffing a turd", that is what we call a CLEAN MISS!

    You would cleanly MISS an Elk at that range and inclination with a 308. [​IMG]

    Cobber-- The pros use a Vectronix PLRF or a Vector 21B with the Angle Indicator feature built into the software. The Marines with low budgets use a mechanical angle indicator with a pivot point, but will soon be getting 21B units.

    [ 10-06-2004: Message edited by: Antslayer ]
     
  9. Dave King

    Dave King Well-Known Member

    Messages:
    2,362
    Joined:
    May 3, 2001
    Antslayer

    You're correct but this is a fairly extreme example you offer but still inside Mr Barrett's stated 1500 yard offering.

    800 yards at a 40 degree angle, note that I stated "moderate" angles although I offered the Dave King "super exageration" of 90 as out of the question, maybe I should have stated 39 degrees. [​IMG]


    We must all learn to walk before we can run and my belief is that Warren Barrett is in the walk stage of the game wanting to break directly into a run, no disrespect meant. I see no need to befuddle the issue with the extremes of conditions although he states 1500 yards at one point(?). You have already offered that there are other "more correct" methods and I submit that for the vast majority of cases the use of any of the three (3) common methods will be sufficient so perhaps Mr Barrett could use what perhaps 99% of other folks are using with some degree success and when his attempts exceed his method(s) he'll continue the quest. If he were to shoot at an inclined and previously stated 1500 yards I'd believe he'd have a second opportunity to get it correct, "the spotter round method would come into play I believe". (At 1500 yards (personal experience) even small angles come to be a problem which is what you addressed.) There will be enough other issues for him to be concerned with, temperature, winds, geographic elevation, etc. I suspect that once he returns we will see another series of these posts and more "who'da thunk" questions.

    /r
     
  10. Guest

    Guest Guest

    Mr. King--"There will be enough other issues for him to be concerned with, temperature, winds, geographic elevation, etc. I suspect that once he returns we will see another series of these posts and more "who'da thunk" questions."

    I agree with you that there will be more questions.....So here is one....

    With all of the error sources you listed in the above paragragh (temperature, winds, geographic elevation, etc.) why would you advise someone to learn how to do it wrong, and build even more error into their shooting?

    Your above comments seem to be the best case for doing it right the first time.
    [​IMG]
     
  11. CAM

    CAM Well-Known Member

    Messages:
    385
    Joined:
    Jan 2, 2002
    Cobber

    The ACI is in 5 deg increments and seems to work well with my exbal chart also.

    I just count up 5-10-15-20-etc. and go to the chart, also you can guesstamate between the points 5-10-15-17.5-etc.

    This is in no way as good as S1's way but as Dave has said is a stepping stone and no mater how you figure drop you still need to know angle I use my ACI for ANGLE

    " Marines with low budgets use a mechanical angle indicator with a pivot point"

    My low budget mechanical angle indicator with a pivot point is an ACI. hooked to the gun and viewable from shooting position.

    Hope this helps some, if not please disreguard. and get a Vector

    CAM
     
  12. Mysticplayer

    Mysticplayer Writers Guild

    Messages:
    1,459
    Joined:
    Jul 27, 2001
    Living in BC and hunting in very "bumpy" terrain, I would like to offer this suggestion to Warren. In the mountains, all the tech in the world is not going to account for the wind you will face.

    At the ranges you propose (up to 1500yds), you are going to need spotter shoots. When you get to your hunting area, take some time and plink on the near by mountains. I think you will quickly find that wind in rarely ever constant in direction or velocity.

    At some point, you will decide how far is too far with the gear and rests you will be using. Ranging without very good equipment is going to be tough too.

    In this terrain, all the gadgets in the world will not ensure a one shot one hit at ranges much past 500yds in anything besides dead calm. Then you have to deal with the thermals.

    Enjoy your hunt...

    Jerry
     
  13. Dave King

    Dave King Well-Known Member

    Messages:
    2,362
    Joined:
    May 3, 2001
    Antslayer

    There really isn't a correct or incorrect as I see it. There's an easy and difficult and depending on the accuracy required one selects the method. Hence my "buffing a turd" comment previously. If the target zone is large and forgiving (all that's required is a hit in the target zone to accomplish the desired objective) the effort require/expended should not exceed that necessary for the task at hand.

    You had previously stated the "real guys" use this "correct" method and not the "other" method. Being the type person I am, had I been Mr Barrett I'd of headed off into the "correct method" as stated by you and ended up with a conditionally correct (and more precise) but not broad view of the option(s). I believe Mr Barrett had already read your offering before he got to mine (read in posted order) and what I was offering was what I considered he should use for his requested application (a target of large dimensions in a moderate distance & angle application (discount his second post of 1500 yards)).

    This is a "hot" topic with several camps, the "okay, it'll work" and the "perfectionists" being at the ends of the spectrum. I see these things, options/methods, as tools that I pick and choose as perceived conditions warrant. 3.14 works for PI() and so does 3.14159265 (which I know/recall from memory (wasted brain cells mostly)).

    The short answer to your question would probably be, "he had too many options so I though I'd push him a little bit toward the "incorrect" but easier and probably sufficient method". Could be my bad but I often head down the dead-end road of questionable/bad examples.
     
  14. Warren Barrett

    Warren Barrett Well-Known Member

    Messages:
    106
    Joined:
    Mar 10, 2002
    OK gentlemen, your recommendations are appreciated. Although, simple is more convenient, I don`t mind doing the math for precision work situations when time is available.
    Could someone lead me in the right direction to find the correction factors for shot angles broken down into 5 degree incriments or less?
    This is one varable that I`d like to eliminate if possible with some others already mentioned, this is the only one in question.
    Thanks for all of the replies, Warren.