StrelokPro ELR help

[AndrewKing]

So as I shoot further I notice my impacts become more off. Shooting low. At 1500 I was like 10 feet low. But at 1000 I was dead on. When I went to “true” the velocity to see what was going on at 1500 it said my velocity had dropped like 200 FPS. But I knew that was wrong and went back to 1000 and was dead on again. The only thing I could think of is a drop in BC due to the velocity. How do you all get the velocity and BC at the target to make your longer shots more accurate? I don’t really want to buy a Doppler.

I’m shooting 6.5 CM and I’ve been shooting factory loaded 140 ELDM but am currently working up a load for the 140 RDFs so with this new load I’d like to be able to get it all right from the start.

This is my first steps into ELR shooting so I’m kind of in unknown territory here for me.

 

[jaybigboy34]

If the bullet is traveling supersonic, then you use the truing feature to true the velocity. If the bullet is traveling subsonic, use the truing feature to true the BC. I would assume at 1500 the bullet is transonic or subsonic. Try truing the BC at that distance and then test again at 1000 to see if you are still on.

 

[TRAC]

So as I shoot further I notice my impacts become more off. Shooting low. At 1500 I was like 10 feet low. But at 1000 I was dead on. When I went to “true” the velocity to see what was going on at 1500 it said my velocity had dropped like 200 FPS. But I knew that was wrong and went back to 1000 and was dead on again. The only thing I could think of is a drop in BC due to the velocity. How do you all get the velocity and BC at the target to make your longer shots more accurate? I don’t really want to buy a Doppler.

I’m shooting 6.5 CM and I’ve been shooting factory loaded 140 ELDM but am currently working up a load for the 140 RDFs so with this new load I’d like to be able to get it all right from the start.

This is my first steps into ELR shooting so I’m kind of in unknown territory here for me.

Usually if I measure muzzle velocity I true BC value until I get to real life values +/- 0.1 mil maximum 0.2 mils difference from 500 m to 1400 m.
Can you please show us all your data?
Environment data for that day and your real drops?

 

[Deleted member 113831]

So as I shoot further I notice my impacts become more off. Shooting low. At 1500 I was like 10 feet low. But at 1000 I was dead on. When I went to “true” the velocity to see what was going on at 1500 it said my velocity had dropped like 200 FPS. But I knew that was wrong and went back to 1000 and was dead on again. The only thing I could think of is a drop in BC due to the velocity. How do you all get the velocity and BC at the target to make your longer shots more accurate? I don’t really want to buy a Doppler.

I’m shooting 6.5 CM and I’ve been shooting factory loaded 140 ELDM but am currently working up a load for the 140 RDFs so with this new load I’d like to be able to get it all right from the start.

This is my first steps into ELR shooting so I’m kind of in unknown territory here for me.

Is your muzzle velocity 2512fps? That's really slow. Secondly, your BC bands are too close together.

The first BC is your initial BC with your muzzle velocity, the second is usually somewhere between 1900-1600 fps, the third is usually after sub-sonic.

 

[Pvt.Donut]

Yeah, velocities seem super slow. I have a 20" barrel and can easily hit the low 2700's. Here is what Litz has for BC's at speeds:

3000-2500 0.327 G7/0.659 G1
2500-2000 0.319 G7/0.635 G1
2000-1500 0.317 G7/0.597 G1
1500- 0.319 G7/0.567 G1

For 1500 yards you are for sure subsonic so I'd suggest playing with the BC until the drop matches.

 

[VaRandy]

Start with the basics. Do you have the scope distance from the bore correct, elevation, etc. Be sure you do the full click test to get the actual click value.

 

[JayB]

Igor runs a facebook group for Strelok, maybe post your question there and see what he thinks of it? Also I am wondering if the CDM in applied ballistics device or AB app would be able to solve for ELR more accurately?

 

[Clearlight]

^^ CDMs are gtg for me . Unless you are running FFS and can shoot a lot , and collect many data points
including well into subsonic flight , there is likely to be elevation solution error .

 

[Jeffvn]

If you are shooting a Hornady ELD-M, go to the Hornady site and dig into the specifics of the bullet data. Hornady has on their site banded velocity BCs for alm,ost all of their bullets. You want to input as many as you can get. (e.g. Flat Line can give you at least 5 or 6 banded BCs for their individual pills; AB custom drag curves are something like 12 velocity bands each with a separate B.C.)

Jeffvn

 

[JayB]

I just remembered that Hornady has an app called Hornady. It contains a 4DOF engine and has ballistics data for all the hornady ELD bullets plus some other brands. It supposedly is very accurate. App is free and probably worth trying out and see if it provides better solution than strelok?

https://www.hornady.com/team-hornady/ballistic-calculators/4dof-ballistic-calculator/overview

 

[Jeffvn]

From the Hornady site: I know they are trying to make things clear, but the 300 yard statement will vary a LOT depending upon the initial velocities at the muzzle.

https://www.hornady.com/support/ballistic-coefficient

Looks like only 3 velocity bands. my mistake.

Jeffvn