Kestrel 5700 Elite Gun Setup - Solution is way off

[devldogs55]

I know there's another thread similar to this, but I'm trying not to hijack it. I'm sure there is something I'm entering wrong into my gun profile. The problem is at 310yards where Kestrel tells me to come up 1.26mils but I actually need 3.4mils for a hit. The range was confirmed with my laser rangefinder, and it's on a square range with distance markers.. other shooters are able to use 310yds for their DOPE.

Gun: RBros Rifles in .308 Win. Muzzle Velocity is 2698 with 175gr RDF 1:10 twist
Scope is Razor HD AMG - MRAD

My method to get set up was to create a gun profile at the house and then upload it via bluetooth to the Kestrel. Once I'm at the range, I get the Kestrel ready to go, and record my environmentals on paper. I zero my rifle at 100 yards, and then go to the Kestrel for my solution. I know I've gotta be missing something, and it's driving me crazy!

<a href="http://s133.photobucket.com/user/devldogs55/media/Mobile%20Uploads/E5AACC3D-EB4C-474C-BCA1-2AB8CD851E93_zpsm2y0qlax.png.html" target="_blank"><img src="http://i133.photobucket.com/albums/q78/devldogs55/Mobile%20Uploads/E5AACC3D-EB4C-474C-BCA1-2AB8CD851E93_zpsm2y0qlax.png" border="0" alt=" photo E5AACC3D-EB4C-474C-BCA1-2AB8CD851E93_zpsm2y0qlax.png"/></a>

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I am pretty certain my zero height is correct. My only guess is the way the scope data is set up could be wrong - I think I'm telling the calculator that it's 10 clicks per mil. My only other guess is something about the way I have environmentals set up on the kestrel.

 

[Stag556]

Just a quick glance at your screenshot.... the ballistic coefficient is entered as 1.000. That may be the issue.


Sent from my iPhone using Tapatalk

 

[devldogs55]

I should have mentioned that I'm using the Litz custom curve for the drag model and their BC is proprietary information so it always shows up as 1.000

 

[pell1203]

About +1.3 Mils is right about where you should be dialing to get to 310 yards. Is this a true and tested scope? That could be your problem.

Have you done a tall target test on it? Assuming you have a good known 100 yard zero, take a piece of cardboard about 4' high, put a target dot near the bottom and run a vertical line up the cardboard from the dot. Set your target out at 100 yards making sure the line is plumb to vertical.

1. Set your rifle to your 100 yd zero and shoot one round at the dot. Your POI should be on the dot, or very close to it.
2. Dial + 5.0 Mils.and again aim at the dot. Your POI for this round should be very close to 18" above the dot very close to the vertical line.
3. Dial and additional 5.0 Mils up for a total of 10 Mils above your original 100 yd zero. Again, aim at the zero dot and fire a round. This one should hit approximately 36" above your aiming dot, close to the vertical line.
4. Dial down 7.5 Mils, Aim at the zero dot and fire another round. Your POI should be 9" above the aiming dot (halfway between your 1st and second shot) along the vertical line.
5. Dial down another 2.5 Mils. This should coincide with your original zero starting point. Aim at the dot and shoot again. Your POI should be the original dot.

If you cannot confirm these hits at the expected distances, then your scope may be the issue.

 

[devldogs55]

I made up a tall target/tracking target last night and that was going to be my test for this weekend. I'll give it a go.

 

[BallisticSam]

I hope your AMG isn't at fault. You could also try making the clicks per mil .10 and not using a Litz curve and see what happens.....but its giving you the right amount of up elevation for 310....I'd check everything from scope base to rings.......even make sure you don't have an MOA turret on your Mil scope.....things get produced on Fridays too....

 

[devldogs55]

I did check the turret and it's marked .1 mil/ click. What's strange is that it's repeatable at 3.4 mils. This is strange - especially since the solution should be correct.

ill try a different drag model.

 

[Blowby]

Interesting.

Lets say 1.26 Mil = 13 clicks.
13 clicks in MOA = 3.25 which is pretty close to the DOPE you see.

 

[pell1203]

Tall target test will tell all if there is a turret mismatch, mislabeling, or erector issue.

Is scope actually marked in mils (i. e., 10 hash marks between mils) or are there only 4 hash marks between major markings?

Picture of turret may help.

 

[devldogs55]

I'll try and get out today or tomorrow for the tall target. It would be a mis-labeling, as I did double check to make sure not only the turrets are marked MRAD, but the zero indicator under the cap is also in graduations of 10 and not 4.

I also have e-mailed back and forth with Vortex CS, and they've been really helpful. They suspected the turret was slipping because the set screws were not tight enough. I was pretty confident this was not the issue, but continued troubleshooting that with them and I think we are past that issue now. They are forwarding my issue on to the product development team to see if they have any answers.

 

[devldogs55]

Interesting.

Lets say 1.26 Mil = 13 clicks.
13 clicks in MOA = 3.25 which is pretty close to the DOPE you see.

Even before you did this math, this is something I suspected in the back of my head. I'll bring that up with Vortex CS if we can't get anything figured out. Wouldn't that be something! A MOA scope labeled as a MIL scope.

I would have that kind of luck.

 

[devldogs55]

Vortex was right.. Made sure the set screws were evenly snug - dialed in dope and PING! Went out to 505yds and dialed in (ironically) 3.4 mils and here's the results.

<iframe width="720" height="480" src="https://www.youtube.com/embed/Q0tAHI36lIg" frameborder="0" allowfullscreen></iframe>

 

[pell1203]

Nice you got it worked out! Sometimes it's just the simple things that bite you in the ass!

 

[devldogs55]

Thanks for the help everyone!

 

[BallisticSam]

Wow that is awesome! Glad it wasn't something worse.