Question about "movers"

C

cdn shooter

CGN frequent flyer
Rating - 98.5%
65   1   1
Figured someone here might have an answer for this. Google is coming up empty.

Are there two different calculations for lead depending on if you're "tracking" or "trapping"?
The reason I ask is I'm trying to determine lead for one of the local comp stages that I shoot regularly.
The stage is a moving target that travels about 25km an hour on a zip line at 75m and it must be shot offhand. The fast movement at close distance requires a tracking technique.
 
The lead will be the same whether you're tracking or trapping. Lead depends on angle to the target and velocity of the bullet. You can use a ballistics program to figure how much in MOA or mils you need to lead. Just plug in the various details.
 
I am assuming that there is a different calculation based on reaction time.....

If you are tracking a target, then the shooters reaction time has no real effect, but if you are trapping, once the target reaches the designated spot, your eyes have to observe it, brain has to process it, the signal has to get sent to your finger to pull the trigger, and the trigger has to get pulled....

I believe the average human reaction time is .25 of a second.
25 km/h works out to
25000 Meters per hour
416 Meters per minute
6.9M/sec.....


so, in the .25 of a second it takes for you to observe, process what you've seen, and react to it, the target will have moved an additional ~1.7 meters which is more then enough to make you miss a figure 11 target. I'm assuming you'd have to account for that in the equation. If you use a trapping method, but anticipate the time to fire rather then waiting to observe it, the lag introduced by reacting is negated. I would expect no variance in the equation to calculating the lead when you anticipate the shot when you trap..
 
RifleDude said:
The lead will be the same whether you're tracking or trapping. Lead depends on angle to the target and velocity of the bullet. You can use a ballistics program to figure how much in MOA or mils you need to lead. Just plug in the various details.
Click to expand...
The variable that the calculators can't predict is your "personal lock time". The time delay from when your brain says "shoot" to when your finger breaks the shot. The calculators assume that's zero. On a walking speed mover, I generally trap and add 1 or 2 clicks for my personal lock time. On a high speed mover, like 25kmh, I'd probably track it like a wing shooter.
 
Thanks guys, makes sense. I thought that the swing on tracking would have more effect than that. But it makes perfect sense that the intangible difference is your own lock time. Now I just have to get an accurate speed of the target. I'm just guessing it's 25kph...I figured it's moving about the speed of a person sprinting.
 
Hahahaha..yup..he is running almost. The one we shot at Rock lake and snipers hide were roughly 3 to 4 mph. 800 yard deal at the hide was on a slight angle as well which changed stuff a little on the one sweep when you engaged the target
 
Your "personal lock time" has to be taken into account even when "trapping". I'm assuming you let the target reach a certain point in your crosshairs, say 1 mil to right of centre as predicted by your ballistics program. You have to add, say, 0.2mil for your reaction time. So start to pull the trigger at 0.8mil in the reticle. You will have to determine through lots of practice how much your reaction time actually is. 25km/hr is very fast and it takes a skilled operator to make good hits at that target. I suggest you practice as much as you can. As mentioned before, the tracking method is probably easier in this case because with a target moving that fast, you can't see the target in your scope until it's almost too late to react when trapping.
 
Last edited:
Ambushing is useful on variable speed targets, or confined positions.
Tracking is more effective on linear speed targets given that your shooting position allows the movement and has the stability to smoothly do so.
75m at 25km/hr ? If it's a generous target, a secondary optic might actually be useful there.
 
You must log in or register to reply here.
Back
Top Bottom