Shooting movers?

[hlee]

Ok, I've had them break some stuff, but that's not what I'm talking about...

I found an equation on-line for calculating lead, incorporating the target speed in mph, the target distance, and the time of flight of the bullet. This is easy enough to use and create a chart with yardage and speeds. The local match where I've been shooting gives ranges, and a range finder is easy enough to carry if yardages are not given. But, I don't have a way to measure target speed. It occurred to me that converting target speed from mph to mrad per sec would eliminate the linear measurement conversion and allow me to measure the angular speed with my reticle. A chart with yardages and angular speed is as easy to create as linear speed.

Has anyone done this? My math says (mradps)(yardage)/488.89 = mph.

The equation I found says ((mph)(1.467)(ToF))/((yardage)(0.003))=lead in mrad.

That simplifies the equation to (mils per sec)(ToF in sec)= mil lead. Of course, now that I look at it, this should be fundamentally correct.

Ok, how do you prepare for movers? I'm building a chart in 1/2 mil per sec and 25 yard intervals out to 10 mil per sec. I've got ToF info from streloc for my load and typical environmental. Too granular? Not granular enough? Do you just SWAG your first shot? Hide at the stage until several other shooters have given you the dope you need?

I am intentionally omitting wind here. What am I missing? Thanks.

 

[Sheldon N]

A) Mil the distance of the end points of the mover, or other reference points.
B) Use stopwatch to measure time of travel.

Divide A by B to get the mover speed in Mils/Second.

Multiply Mover speed by your time of flight for the given yardage. This is your lead to center of target.

Dial wind, ambush target. Correct for wind changes by timing the break of your shot towards left edge or right edge, etc.

 

[hlee]

A) Mil the distance of the end points of the mover, or other reference points.
B) Use stopwatch to measure time of travel.

Divide A by B to get the mover speed in Mils/Second.

Multiply Mover speed by your time of flight for the given yardage. This is your lead to center of target.

Dial wind, ambush target. Correct for wind changes by timing the break of your shot towards left edge or right edge, etc.

We're on the same page.

 

[Hollywood 6mm]

For those that already have a Kestrel, it has a function built in (albeit buried in the menus) to do this. I've used it more than once at matches, and it's been spot on every time.

 

[PinesAndProjectiles]

Strelok will do this for you.

 

[Sheldon N]

We're on the same page.

I started doing this and entirely bypassing mph in the calculations because often the speed that was provided was was wrong.