5700 AB Doesn't Match Strelok

[PinesAndProjectiles]

Warning: I'm new to the Kestrel AB. My last Kestrel didnt have a Ballistics solver and this is all new to me so feel free to think I'm retarded.

I upgraded to a Kestrel 5700 Elite recently.

I've been playing around with it and was matching up my data to Strelok Pro, which I've been using with good results, and the data doesn't match.

Strelok says that at 400 yards, I need 1.7 Mils, but the Kestrel says 1.81 Mils.

I'm sure it's something simple but it's getting the best of me.

I've done searches, both on Al Gore's interwebs and on the Hide with no luck.

Any ideas?

Thanks.

 

[Dave62677]

all the ballistic app just get you to approximate reach. you need to true it yourself at the field. No all ballistic apps are equal. Most app have the option to input correction %.

 

[ForgeValley]

Could be any number of things, setup can be tricky to get just right between the two. First thing I would check would be weather variables, rifle setup like sight height, and BCs. But as said above, there is always going to be a little variation, even if they use the same models.

 

[JTJACKSON]

Not retarded at all. In my opinion, shoot every hundred yards (to as far as you'll feasibly shoot the rifle) without a ballistic solver and record the actual data. Then get the solver to match actual data. When using strelok or other apps, be careful about the info you input, including gun information, bullet information, and environmental conditions. It's been said a zillion times on here that garbage in=garbage out, and that is certainly true.

As a side note, if you are planning on shooting elr targets, a g7 ballistic coefficient is said to be better in strelok and ab.

If this info is too basic, I apologize, but that's what I've done for years and it's worked for me. But there a lot of more experienced shooters on here than I am who could certainly share more valuable tips. Hope this helps

 

[Laughing_Jackal]

I know having a "Wind 1" value in the Kestrel can cause your real world elevation to be off a bit due to the built-in "aero-dynamic jump" feature. If you haven't already, you might try putting "Wind 1" to zero, and just enter a value for "Wind 2" (which will essentially disable aero-dynamic jump from your output).

I started with a Kestrel 5700 Elite AB, but now I pretty much only use Strelok Pro.

 

[PinesAndProjectiles]

Not retarded at all. In my opinion, shoot every hundred yards (to as far as you'll feasibly shoot the rifle) without a ballistic solver and record the actual data. Then get the solver to match actual data. When using strelok or other apps, be careful about the info you input, including gun information, bullet information, and environmental conditions. It's been said a zillion times on here that garbage in=garbage out, and that is certainly true.

As a side note, if you are planning on shooting elr targets, a g7 ballistic coefficient is said to be better in strelok and ab.

If this info is too basic, I apologize, but that's what I've done for years and it's worked for me. But there a lot of more experienced shooters on here than I am who could certainly share more valuable tips. Hope this helps

Thanks JTJ. I pulled all my data from Strelok to put into the Kestrel app and it all matches.

The problem is, I don't have regular access to a range that will allow me to shoot every 100 yards out to anything past 100. It makes this hobby rather difficult.

 

[PinesAndProjectiles]

I know having a "Wind 1" value in the Kestrel can cause your real world elevation to be off a bit due to the built-in "aero-dynamic jump" feature. If you haven't already, you might try putting "Wind 1" to zero, and just enter a value for "Wind 2" (which will essentially disable aero-dynamic jump from your output).

I started with a Kestrel 5700 Elite AB, but now I pretty much only use Strelok Pro.

I'll take a look at this. I thought I had read something about Coriolis, Spin Drift and other like settings messing with elevation calculations somewhere and I'm not sure if I can turn them off, but I'll take a look.

 

[Laughing_Jackal]

I'll take a look at this. I thought I had read something about Coriolis, Spin Drift and other like settings messing with elevation calculations somewhere and I'm not sure if I can turn them off, but I'll take a look.

I'm 99% sure you can disable Coriolis and Spin drift, but I'd be surprised if any of those are playing a significant part in elevation discrepancies at 400yds.

There's really not an "off switch" for Aerodynamic jump that I'm aware of, other than simply putting 0mph for Wind 1. And that setting will certainly play with your elevation numbers.

 

[EchoDeltaSierra]

First off, what are you shooting at 400y that 0.11 mills would make the difference between hit and miss?

I have a few of profiles configured in my Kestrel 5700 that were MV trued (multiple times) with drop data from 1000y F-class pull-up targets. When shooting, I rely on my Kestrel numbers and get WAY more hits than with any app used. I still use several other ballistic calculator apps, but only for modeling loads or helping others who are getting started.

 

[PinesAndProjectiles]

First off, what are you shooting at 400y that 0.11 mills would make the difference between hit and miss?.

Crabs on a dead hooker.

I was just using 400 yards as an example. The further out, the larger the difference.

 

[EchoDeltaSierra]

Crabs on a dead hooker.

That. Was. Awesome.

I was just using 400 yards as an example. The further out, the larger the difference.

I've found the quickest way to get to accurate data is to true up the Kestrel at range. From my experience, MV truing at 1000y (800y for 308) is what gives me the data that makes reliable hits from 200-1200y. Other ballistic apps have a varying (and interesting) margin of error and some I've figured out how to adjust to mostly match the 5700. All I know is that there are way more hist beyond 400 yards using the 5700's data.

 

[djarecke]

I still use wind 1 in my calculations to get an accurate drop. It would be a lot easier to talk you through this over the phone. You can PM me if you’d like me to talk you through it. In the meantime, make sure you’ve got a good height over Bore and we can figure out the rest. Also - do you REALLY have a good zero or might you be .3” high and not realizing it?

 

[PinesAndProjectiles]

I still use wind 1 in my calculations to get an accurate drop. It would be a lot easier to talk you through this over the phone. You can PM me if you’d like me to talk you through it. In the meantime, make sure you’ve got a good height over Bore and we can figure out the rest. Also - do you REALLY have a good zero or might you be .3” high and not realizing it?

I do have a zero offset of -.1 Mil entered in both Strelok and the Kestrel.

I'm going to make a few calls and see if I can find access to a longer range this weekend and get some field play.

 

[Dthomas3523]

I do have a zero offset of -.1 Mil entered in both Strelok and the Kestrel.

I'm going to make a few calls and see if I can find access to a longer range this weekend and get some field play.

Turn off spin drift, and set latitude to 0 or 1, I can’t remember. That will make sure spin and Coriolis is off.

See if that helps a little. It may or may not.

 

[Subwrx300]

Are you using the Kestel Link ballistics app to input your rifle/cartidge data? If you are, double check all data for rifle after you input a new rifle/load.

On my unit (not sure which firmware), as I'm entering new bullet/rifle, changing certain parameters will reset some of the data I've already entered back to default (namely zero range always reverts to 109yds, caliber, weight and bc constantly reset). Not sure why it does this as it's a PITA, but it has caused a few loads to give mismatched solutions. After correcting, I've usually been within 1/2moa or so out to 900-1000 yards.

And also, as @Dthomas3523 suggested, I turn off spin drift and set wind to 0 when creating new loads. While I've had good solutions using both spin drift and Coriolis, I've had some odd ones also. To use it, you need to ensure all data is PERFECT (latitude, firing azimuth, wind orientation, BC, and velocity). I still keep it off 90% of the time inside 1200yds.

Regarding zero offset values, they have caused me larger headaches than I care to admit. My procedure to verify data is as follows:

• Shoot 5 shot 100yd zero group (toss cold bore shot)
• Shoot 3 shot at 600-800yds; write scope value and any difference observed on group center
• Shoot 3 shot 100 zero (new aiming point)
• Shoot 3 shot 1000-1300yds; write scope value and any difference
• Shoot 3 shot group 100 zero (new aiming point)

As long as zero group cemters remain dead flat (elevation within .1MOA or less), I adjust MV to line up the 800yd, then BC to get 1100-1300 data to match. If it's slightly off, I keep playing with MV/BC to get it to match real-world and I'm done.

If zero shifts slightly, I might add/subtract from real world drop values but generally if my Kestrel gets me to within +-.25MOA/.1Mil, it's good enough for my matches. Just a 10fps change in avg velocity for the day or as ammo heats/cools is enough to make you go crazy if trying to be too exacting.