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.

Location: The rifle range, or archery range or behind the computer in Alaska

Posts: 3,595

Re: Riflemans Rule

Quote:

Originally Posted by Browninglover1

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.

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.

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Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.

but the military and almost every other long range school will continue to teach "The riflemans rule"

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.

Quote:

Originally Posted by Sully2

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

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...

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Courage is just fear that has said it's prayers.

The people trying to say the 2nd Amendment is outdated are probably the same folks that would say the same thing about the Bible.

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...

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

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.

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