Calibrating DSF on Kestrel Ballistics Meter

DSF calibration is important when shooting beyond the supersonic range of a bullet while using a G1 or G7 standard drag model. TIME STAMPS BELOW:
00:06 WHAT IS DSF
Hi, this is Katie from Kestrel and today I am going to talk to you about calibrating your DSF. DSF is your drop scale factor or drag scale factor. We use DSF when we’re going into extreme ranges, when you’re pushing into subsonic. Unlike muzzle velocity, when we give you the number for calibrating your DSF we want you to go beyond that point. We’re going to go through all the steps right now so that you can use this process.
00:28 HOW TO UPDATE ENVIRONMENTALS
STEP 1: First thing we’re going to do is update our environmentals, or atmospherics. We’re going to go down to enviro, toggle over to live, and then swing the Kestrel. Swinging the Kestrel allows ambient temperatures to acclimate to what we we’re actually feeling. So, it allows these sensors to get cleaned out. If you have enough wind flow, you can just hold it up into the air and the air is going to blow past this thermistor. That’s what you’re really looking for. Once you see that your temperature is acclimated, you’re just going to toggle it off to lock. That’s going to lock in all of your environmental conditions for your day of shooting.
01:01 CAPTURE DIRECTION OF FIRE
STEP 2: The next step we’re going to do is capture our direction of fire. You just point the Kestrel down range. Highlight TGT. Red button. And that’s going to capture your direction of fire. Red button again to lock it in.
01:14 UPDATE WIND SPEED
STEP 3: Up next, is updating our wind speeds. Pop open the impeller cover, find the wind direction, and same thing with that shortcut button. Use the red button, lock it in. Give it at least 5-10 seconds to get a good average. And then red button again. That’s going to give us our wind.
01:33 HOW TO CALIBRATE DSF ON YOUR KESTREL
STEP 4: Now, we’re going to go into the gun. Highlight your gun that you’re using. Scroll all the way down through that gun and go to Cal DSF. Center button to go into Cal DSF. Now, the number that it’s giving you up in the upper right-hand corner, is a number that the unit goes into transonic. So, this weapon system goes into transonic at 1525 meters. We actually want to go anywhere beyond that, so we’re calibrating for our drop. Were kind of tweaking that curve at the other end.
02:02
So, we actually have a range here at 1600 meters. I’m going to scroll up to 1600. And my drop is now telling me that it should be at 23.6 mils. So, all I’m going to do is dial up as far as I can on my scope, I’m going to hold up my reticle at 23.6, and then go ahead and fire. We’re looking for confirmation of elevation, not windage. But of course, wind is always a factor at these long ranges.
02:41
So, we just shot out to 1600 and had impacts on 2 of the 3 rounds. Which was really good, we didn’t have to adjust our Cal DSF. Now this happened because I used a custom curve and a known muzzle velocity. I already trued my muzzle velocity, so my curve was really on. If I was using just a G1 or a G7, I would expect to have a greater need for the Cal DSF.
03:03
So, we have a really good chart here that shows you when you really need to calibrate DSF and when you can be most assured that the data that you’re using is going to be good. Anytime that you push out to long range though, I recommend that you take the time to collect your data and collect it on your DSF.