Riflemans Rule

Discussion in 'Long Range Hunting & Shooting' started by load, Mar 31, 2012.

  1. load

    load Well-Known Member

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    Boy I creamed on another thread for mentioning this way to calculate angle. I was made fun of for my "fussy, made up, equation!" which I pointed out wasn't "MY" equation but simply "the Riflemans Rule". most on that thread seemed to like an "improved" version which is cos x drop and others yet for "Sierras rule". Well here it is on video.... The Riflemans Rule

    http://www.longrangehunting.com/forums/f73/correcting-inclined-shots-riflemans-rule-89407/
     
  2. Michael Eichele

    Michael Eichele Well-Known Member

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    No offense but the rifleman's rule (cos*range) will work at medium ranges with minor angles.

    Bottom line, 600 yards shots with 20 degree angles (very common real world hunting senarios) the rifleman's rule is not good enough. With 3000 FPS and a .6 BC the rifleman's rule will be 5" off. 5" off may not be bad on a large target but on a small deer can be the difference between a miss or worse yet a wounded loss versus a clean kill.

    Cos*drop or holdover is much more accurate but still not as accurate as the Sierra rule as you call it.

    Again, no offense but these are the facts. When it comes to long range hunting, do it right. There is no half a$$ed methods that lead to consistent clean kills at distance.

    Many here will argue with you as well about it. Forget the video. Go do it in the real world and see for yourself.

    M
     

  3. load

    load Well-Known Member

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    see what I mean!:D

    personally i have been using drop x cos :rolleyes: it is more accurate but the military and almost every other long range school will continue to teach "The riflemans rule" gun)
    I just have to point out that its not "MY" bad advise nor "my fussy math" to those that like to chastise... chastise the "pros" that teach it.

    I personally think that Huskemaws system is a half a$$ wanna be short cut that leads to inconsistent shooting as one calc can not do it all.
     
  4. proload

    proload Well-Known Member

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    Long range hunting means different things to different people ... I'm one of those who doesn't shoot beyond 400 - 500m, but I love these forums because I learn so much from those that are going much further than I do with this sport ...

    That said, I found this rule useful and will add it to my quiver of tricks for my hunting in future ... I've always just guessed what the impact of the angle would be on a shot, and to be fair, that has worked well enough for me, but this would be better ... It may not meet the needs of someone shooting 'real' long range, but it's beneficial to me ...

    Thanks.
     
  5. Browninglover1

    Browninglover1 Well-Known Member

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    I have a weird question... when I run the numbers through G7's ballistic calculator (I realize it might not be correct but I don't have any other to use) neither the rifleman's rule nor the drop*cos give the same drop compared to the G7 calculator with a 30 degree angle at 1k.

    Are there programs that will more closely match up to one than the other? In your field experiences does the drop*cos work correctly in every situation you've tried it in?

    I would just like to get a grasp on all this theoretically to try and understand why one is correct and one is not.
     
  6. Sully2

    Sully2 Well-Known Member

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    Use your laser range finder with it already built in.!!
     
  7. sp6x6

    sp6x6 Well-Known Member

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    That was EXACTLY Michael E. point, learn to use what works. Ballistic calc. with proper inputs or a G7 RANGEFINDER set up for rifle.
     
  8. load

    load Well-Known Member

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    ? don't know?:)
     
  9. load

    load Well-Known Member

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    :)>
     
  10. Michael Eichele

    Michael Eichele Well-Known Member

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    Don't forget, there is the line of sight and the line of bullet departure. Your line of sight may be 30 degrees uphill or down hill but the bullet's path is never the same angle. Hence the reason the rifleman's rule or the drop * cos method don't work properly. There are more variables working here than just the line of sight angle, distance and gravity.

    That is why the proper equasion also takes into consideration other ballistic information.
     
  11. Bravo 4

    Bravo 4 Well-Known Member

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    And they should as it is a technique (one of several they should teach). A technique as Michael Eichele pointed out for medium ranges, and also good for guys using hold over/hold off with iron sights, CCO, or ACOG.

    Wouldn't this be the rifleman method, don't they multiply the range times the cosine? Unless it has your ballistic computer built in like the G7 rangefinder...
     
  12. Sully2

    Sully2 Well-Known Member

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    Beats me guy?? I just know it works however the machine calculates it!!
     
  13. LRSickle

    LRSickle Well-Known Member

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    What's the Sierra method?
     
  14. Greyfox

    Greyfox Well-Known Member

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    I have used the riflemans rule for quite a while for shots out to about 500 yards on game at smaller angles of 30 degrees or less and it has worked ok. This rule simply multiplies the look angle cosine by the slant distance to get a correction range in meters or yards. My understanding(sticking my neck out), is that the basic problem for longer ranges and steeper angles is that this rule does not take into account your specific load's change in velocity that occurs over the distance to the shot. It also doesn't account for changes in the pull of gravity or air density that occur if the angle is steep enough to result in a large elevation difference between your shooting position and where the target is. It also doesn't account for gravitation effects between up or down shots. It's not perfect, but a way to better correct for at least the change in velocity effect at most practical hunting angles is to multiply the same cosine factor of the look angle of the slant range by the drop in inches that would be used for the shot as if that slant range distance was a level reading. You are basically correcting a drop value instead of a distance value which helps correct for the velocity difference between you position and your target. In recent years, I have just plugged the look angle into my FTE ballistic calculator that appears to work well, at least at the distances and angle I hunt in which the angles are not extreme. I'm not sure what the algorithm is in the devise, but it very likely corrects for the velocity, and maybe the other factors of up/ down, air density etc. I have tested my recently purchased G7 rangefinder and compared it to the FTE for my load and the drop data is identical for a 400 yard, 13 degree angle. I will try longer ranges and steeper angles when I get a chance.