chrono vs shot data

[Yotebuster]

So I went out this morning shooting, Dialed in zero at 200 yds with both my guns I took. I Had chrono'd the loads the week before. When I plugged all my data into my phone using Strelok app doubled and tripled checked all my data entered, I pulled up my drop table on the phone. Dialed for what it said for 500 yds for both guns both hit high. Went back checked all entered data again and was spot on. Shot again both guns way high. So I adjusted my velocity to match where the guns hit dead on at 500 yds. But no way my gun can be shooting the speed it says. My 7mm rem mag possibly but the 25-06 is no way shooting a berger 115 at 3400fps chrono said it was shooting 3197 with a 14 fps spread over 4 shots so load is shooting well? Any ideas what is going on??? I got home and checked to make sure all my data was entered correctly and it seems it all is.

 

[Yotebuster]

One thing i did not consider Quess could be my scopes both track well but could move more than they say per click better do a box test

 

[Greyfox]

I tried the Strelok App a while back and found that compared to my Shooter App and Gunwerks G7 RF's ballistic calculators, with my 6.5x284 at 500 yards, the Strelock app with the same inputs called for a 8.9 MOA drop compared to 6.5 MOA with Shooter and the G7, both which I have confirmed out to 1200 yards. I checked the inputs and set-up several times and was never able to figure out why the Strelock gave higher values. You might try Shooter to see if this could be the problem.

 

[bill123]

Before buying another app, test it out with s free calculator online. Applied Ballistics is here: Ballistics Calculator | Applied Ballistics, LLC

 

[MBird]

you have the basics ground work for the 500 yard shot, now fine to it

Did you consider l the other variables ?

did the Temp change between the your data collection and applying them

Did you adjust for elevation above sea level

What about Barometric pressure

If you are dialing your scope for the shot: why sight in at 200

Ballistic programs are set to a general standard 59 deg, sea level, 29.95 pressure.

V/R
M.Bird

 

[Yotebuster]

yes I adjusted for Temp ,Elevation, Barometric pressure ,Humidity, scope height, Barrel twist, BC velocity everything I can think of was right on. Went and shot today again to make sure and just going to have to adjust my speed to match what I need to get the correct drop chart but was dead on out to 500 yds by doing that.

 

[406precision]

We haven't used strelok for sometime as shooter and applied ballistics have garnered better results, but one thing you need to be careful of is that the program is only referencing either station pressure or elevation, but not both.

Jordan@406

 

[Barrelnut]

When I have an issue like this and I am sure the scope it tracking correctly, I adjust the bullet BC in the app to Match the results at distance. I leave Speed (that was documented by the crony) alone. I just feel its a cleaner way to get things to match. That was you always have the chrono speed documented in the app.

 

[406precision]

I'd recommend a tall target test with your scope as well

Jordan@406

 

[Garycrow]

When I have an issue like this and I am sure the scope it tracking correctly, I adjust the bullet BC in the app to Match the results at distance. I leave Speed (that was documented by the crony) alone. I just feel its a cleaner way to get things to match. That was you always have the chrono speed documented in the app.

This is what I do also. If you've measured your speed and are confident in the chronograph then the speed isn't the problem. Assuming all other variables are correctly entered then that leaves B.C. B.C.'s are often inflated by some bullet manufacturers and they're not always consistent either. One rifle can shoot the same bullet to a different B.C., the manufacturers data are only really in their test rifle.

 

[bigngreen]

Before you get crazy what version of Strelok are you running, the free version should get a guy a ways out there but the Pro version is very good but has a poor flow to it but offers some stuff very few other programs will run. The free version really can be hard to get the zero set perfectly since it's just a range, Pro lets you input the exact zero point. Free is also tied to the G1 BC but Pro lets you do customs and G7 BC which will get you out there!
Scope tracking is a biggy along with correct use of station pressure, the pressure can get goofed in free Strelok but you can mess up Pro.
Double check range also.
If your using a Litz G7 BC you won't need to tune it, absolutely leave it alone unless your twist rate is jacked up, even rifle to rifle you won't need to tune it till it's dropped down to 1400-1200 fps maybe! When we have all the best inputs we are still left with a little uncertainly with velocity, a guy can guess the velocity as long as all the other inputs are correct and you'll end up at the same velocity as you would if you started out with a velocity from a Magneto or Oelher.