Shooting low at 1000 yards while using Strelok Pro

[TackDriver2]

Took the 6.5's to the range today, tried out at 1000 yards, and I have been shooting low today, its off like 2 feet. Weeks prior to this, I have shot at 500 yards and all was spot on, and I think temp was in the 80's, and today temp was in the 60's. I'm using temp stable H831SC and H4350. I think it may have something to do with temps. Not quite sure.
I have input all my rifle and scope data in the Strelok Pro, I'm not so familiar with the zero weather stuff, I just purchased this app several weeks ago. Any help is appreciated.

 

[salks]

Why you using G1 BC ? True your G7 B.C. off actual impacts at distance 700 yards +. Then test it at different distances..

 

[morganlamprecht]

Ballistic Coefficient - Hornady Manufacturing, Inc

A-Tip®, ELD® Match, and ELD-X® Ballistic Coefficient Values Hornady originally published “800 yard”* average Ballistic Coefficient (BC) values for ELD-X and ELD Match bullets. This was done to provide the most usable BC from a trajectory prediction st...

www.hornady.com

Check that link out

I’ve never used strelok, but the pic you attached only shows the highest Mach 2.5 BC value being used @ .697…so I’m assuming it doesn’t apply the whole band of BCs

There may be a way to input the variable BCs for the various Mach speeds…there are in other apps, but idk about strelok

Basically BC varies with velocity, you’re currently using the highest BC, but @ 2703 muzzle velocity to 1k yds, that Mach 2.5 number doesn’t apply very long

That’s likely why it was good to 500 yds…your actual BC will likely avg out to somewhere between the Mach 2 and Mach 1.75 number

 

[morganlamprecht]

Also if you’re going to be using Hornady bullets, it wouldn’t be a bad idea to download and check out the Hornady 4dof app

They have the actual drag profiles for most of their bullets in there and bypass the avg BC method all together…it should spit out more accurate data all the way around

 

[AllenOne1]

I don't think the temps are causing bullet drop of 2 MOA but I notice that your temps are in the system backwards. The top temp should be the current weather and the bottom temps "Zeroing Weather" is the weather when you actually zeroed your rifle. Most likely you will need to adjust your BC to match the rifle performance. How did you get your velocity?

 

[TackDriver2]

I don't think the temps are causing bullet drop of 2 MOA but I notice that your temps are in the system backwards. The top temp should be the current weather and the bottom temps "Zeroing Weather" is the weather when you actually zeroed your rifle. Most likely you will need to adjust your BC to match the rifle performance. How did you get your velocity?

I used the P35 Oehler to record velocity several weeks prior. I re-checked my data on the Strelok, you are correct, my weather is off. I remembered the weather was around 80 degrees when I recorded the velocity, and the current weather yesterday was 63 degrees. It should have some correction once I apply the correct weather, it may do need BC adjustment, possibly change from G1 to G7? Should I leave it at G7? For some of my rifles, G1 would be just fine for hunting distances out to 500 yards, would it? Leave G7 for the 1000 yard rifles? I'll redo my tests again soon. Thanks

 

[TackDriver2]

Ballistic Coefficient - Hornady Manufacturing, Inc

A-Tip®, ELD® Match, and ELD-X® Ballistic Coefficient Values Hornady originally published “800 yard”* average Ballistic Coefficient (BC) values for ELD-X and ELD Match bullets. This was done to provide the most usable BC from a trajectory prediction st...

www.hornady.com

Check that link out

I’ve never used strelok, but the pic you attached only shows the highest Mach 2.5 BC value being used @ .697…so I’m assuming it doesn’t apply the whole band of BCs

There may be a way to input the variable BCs for the various Mach speeds…there are in other apps, but idk about strelok

Basically BC varies with velocity, you’re currently using the highest BC, but @ 2703 muzzle velocity to 1k yds, that Mach 2.5 number doesn’t apply very long

That’s likely why it was good to 500 yds…your actual BC will likely avg out to somewhere between the Mach 2 and Mach 1.75 number

That does make sense, thank you. I'll do more research on this.

 

[TackDriver2]

Why you using G1 BC ? True your G7 B.C. off actual impacts at distance 700 yards +. Then test it at different distances..

Good point, I mostly hunt, its why I left it at G1, I'll change it to G7.

I just read that G1 is mainly for flat based bullets and G7 as for boat tails. I should have checked the difference between the two a long time ago. Thanks

 

[morganlamprecht]

This podcast should explain everything well, it’s worth the listen if new to ballistics and wanting to understand the numbers/effects

Either g1 or g7 can work inside super sonic range once tweaked/trued up…the bullets you’re shooting match the g7 shape closer but neither are actual matches for your bullet

 

[Jefe's Dope]

It's not the temps. G1 is old tech, use G7. You may have to true your D.O.P.E. after your initial inputs and speeds.

 

[Tempest 455]

Cant tell you how many times in the pits I heard "thud" and clump of dirt/grass comes flying over head from someone shooting feet low at 1,000 yards and hitting the berm.

1st time out many are low at 1,000 for various reasons. Take a lot of notes on conditions and keep a record of them.

 

[Igor Borisov(Strelok Pro)]

Took the 6.5's to the range today, tried out at 1000 yards, and I have been shooting low today, its off like 2 feet. Weeks prior to this, I have shot at 500 yards and all was spot on, and I think temp was in the 80's, and today temp was in the 60's. I'm using temp stable H831SC and H4350. I think it may have something to do with temps. Not quite sure.
I have input all my rifle and scope data in the Strelok Pro, I'm not so familiar with the zero weather stuff, I just purchased this app several weeks ago. Any help is appreciated.

Try to use G7 multi bc values
Hornady is only manufacturer who published G7 multi bc values: http://www.hornady.com/BC
Please look attached picture how to use it

 

[Long Range 338]

Truing really shouldn’t be done until 800 yards or so. Remember you are simply matching the software to your real world dope. Many get lost in the software and lose the opportunity to observe and learn what is really happening. Take notes while at the range and then true the software at home. Too many distractions while at the range and items get overlooked. At least that has been my experience.

 

[TackDriver2]

Truing really shouldn’t be done until 800 yards or so. Remember you are simply matching the software to your real world dope. Many get lost in the software and lose the opportunity to observe and learn what is really happening. Take notes while at the range and then true the software at home. Too many distractions while at the range and items get overlooked. At least that has been my experience.

I changed from G1 to G7, adjusted weather, and all data, if the 800 yard hits are low, what do I change?

 

[salks]

Adjust dope to get on target. Use strelok truing. It will spit out a G7 B.C. Use that B.C. for all ranges. You will want to test this at some different ranges.

 

[MarshallDodge]

This may have nothing to do with your problem but all powders are temperature sensitive. The powders you are using are less sensitive but still affected.

 

[Long Range 338]

I changed from G1 to G7, adjusted weather, and all data, if the 800 yard hits are low, what do I change?

Once you’ve confirmed your inputs are all accurate, the only things you can adjust are BC and velocity.

Don’t be afraid to adjust the bc, it’s not a fixed number and can vary depending on environmentals and even bullet variations. You shouldn’t have to make large adjustments though.

Also you should look into the banded bc’s as noted by Igor.

My comments were more related to understanding you are making the software match what you observe in the real world, not just expecting the bullet to match the software.

 

[acudaowner]

our first trip to shoot 1k dialed up using Strelok it said to use 9.3 mil dialed it up and shot first 5 shots were 2 clicks high of center and all 5 fit inside the size of my hand , I could ask for nothing more it works if your feeding it good data .

 

[waveslayer]

our first trip to shoot 1k dialed up using Strelok it said to use 9.3 mil dialed it up and shot first 5 shots were 2 clicks high of center and all 5 fit inside the size of my hand , I could ask for nothing more it works if your feeding it good data .

Good data or not, all solvers needed to be trued to match your rifle. BC's change with velocities, this truing your solver to the target... go past 1000 and see if it's still accurate