Trajectory Validation - Strelok+

[Zigjib]

G'day;
I need help understanding this information in Strelok Pro

178gr ELD-M 2478fps (chronographed)
I put the info in Strelok Pro and it told me i needed 4 MRAD for 527m.
Shot F-Class today and needed 4.15 MRAD drop at 527m.
I put the information into Strelok Trajectory Validation

It predicted 4 MRAD, but in Trajectory Validation, it predictions that a drop of 4 MRAD increases my MV to 2512fps.
When i put in 4.15 MRAD, it gives me 2481 fps (within 3fps of my chronographed loads)
I hit "Use this Data" and it updates my MV, but the MRAD drop on the home page still states 4 MRAD.
What am i doing wrong here, because this doesn't make sense to me?

 

[Hecouldgoalltheway]

If you're confident in your mv, try using the validation feature to adjust your BC. You'll need another longer range to truly validate. I use two known distances, like 600y and 1,100y to validate. Conventional wisdom is that you adjust velocity for impacts out to 600y and BC for ranges beyond. But, your BC could be the problem. BC's change rapidly based on velocity.

But, before you change anything, I'd triple check all of my input data.

 

[Hecouldgoalltheway]

In fact, I believe the .308 with the 175 actually lines up best with a G5 BC. If you're using a g1 or a g7, you're BC isn't going to be lined up as well as it can be.

 

[6.5SH]

G'day;
I need help understanding this information in Strelok Pro

178gr ELD-M 2478fps (chronographed)
I put the info in Strelok Pro and it told me i needed 4 MRAD for 527m.
Shot F-Class today and needed 4.15 MRAD drop at 527m.
I put the information into Strelok Trajectory ValidationView attachment 8130563
It predicted 4 MRAD, but in Trajectory Validation, it predictions that a drop of 4 MRAD increases my MV to 2512fps.
When i put in 4.15 MRAD, it gives me 2481 fps (within 3fps of my chronographed loads)
I hit "Use this Data" and it updates my MV, but the MRAD drop on the home page still states 4 MRAD.
What am i doing wrong here, because this doesn't make sense to me?

How are you measuring everything?

You are using mixed units, which Strelok usually handles very well. But things like a scope height of 10.00 CM (nearly 4"), the 4.15 MRAD elevation, 527 meter target distance shooting F-Class stand out as possibly not correct. Are you truly zeroed at 100 meters (in both meanings, zeroed AND at truly that distance.)

 

[Zigjib]

How are you measuring everything?

You are using mixed units, which Strelok usually handles very well. But things like a scope height of 10.00 CM (nearly 4"), the 4.15 MRAD elevation, 527 meter target distance shooting F-Class stand out as possibly not correct. Are you truly zeroed at 100 meters (in both meanings, zeroed AND at truly that distance.)

Yes, those figures are all correct
I'm Australian and we use the metric system

 

[Igor Borisov(Strelok Pro)]

Yes, those figures are all correct
I'm Australian and we use the metric system

10 cm of scope height above barrel looks too much. Are you sure?
If speed is measured make truing of your bc not speed
Also try to use multiple ballistic coefficient (data from Hornady):
.308 Hornady 168 ELD-M
Select G7 drag-model!
0.263 2512
0.259 2232
0.251 1953
In case of multiple ballistic coefficient make truing of bullet speed

 

[Zigjib]

How are you measuring everything?

You are using mixed units, which Strelok usually handles very well. But things like a scope height of 10.00 CM (nearly 4"), the 4.15 MRAD elevation, 527 meter target distance shooting F-Class stand out as possibly not correct. Are you truly zeroed at 100 meters (in both meanings, zeroed AND at truly that distance.)

Yes, those

10 cm of scope height above barrel looks too much. Are you sure?
If speed is measured make truing of your bc not speed
Also try to use multiple ballistic coefficient (data from Hornady):
.308 Hornady 168 ELD-M
Select G7 drag-model!
0.263 2512
0.259 2232
0.251 1953
In case of multiple ballistic coefficient make truing of bullet speed

oh snap! the man himself!
I doubled measured and using my tape measure i got 10cm, but using a steel ruler i got 9.6cms.
It's AR 10 Type receiver model with a unimount ontop with a 20MOA bias.
BUT!
Got some advice from a bloke who messaged me to save me some embarassment lol, but I think it's a good lesson of shit in shit out.....
Changing the measurement to 9.6cm got me closer, but, it's how i got my weather meter information that knackered me.

When we started shooting it was 18 degrees. Got the Kestrel data at that time. Shot for 4 hours, finished the sess with a rezero confirmation, dialed it all out, slipped the zero stop and reset the zero.... WELL.... i neglected to update the temp for the mid afternoon off the mid morning!

Updated the weather and bingo. perfection!
Thanks for all the help gents!
Igor, stay safe brother!