IStrelok clicks?

[itsTyrtruion]

Handload for rem700LR in 7mm Rem mag
58.5 grains 4831sc pushing 175g ELD-X at 2755-2768fps (chrono)
Zero at 101yds

Target at 575, input all accurate info
3.3 MRAD or 68.46” drop.

Squeeze first one off and see dirt impact about a foot over the target

Several shots and clicks later I find the target and am sitting at 2.6 MRAD

Checked my zero
Checked the scopes tracking
Everything seems to be fine.

Why would there be a .7 MRAD difference at 575 yards?

Any ideas?


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[AKironhead]

You have bad data input somewhere. I just ran your numbers in 3 different ballistic apps and got 2.65-2.8 mils for 575yds

 

[itsTyrtruion]

You have bad data input somewhere. I just ran your numbers in 3 different ballistic apps and got 2.65-2.8 mils for 575yds

I started over and put all the info in again and came up with the same 3.31. What apps are you using?

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[AKironhead]

Applied Ballistics, Trasol, and Shooter. The Litz BC# is .700 G1 for the 175 ELDX, try playing around with that number a bit to true up your software to whats actually happening. I would also try turning off temp sensitivity, for whatever reason, I've seen that screw up data on multiple solvers.

 

[itsTyrtruion]

I’ll give that a try. Just entered info inyo a hornady app and got 2.9mrad.

Box of bullets says .675 for g1 bc


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[2five7]

I tried Strelok and got 3.4 MRAD, changed to a 200 yard zero and got 2.8 MRAD. This was for 5000' elevation. What elevation are you at?

 

[Macintosh]

Im a new strelok user and had exactly the same thing happen--getting consistently high misses from the app. A friend was helping me and ran it through his applied ballistics app and also got a bit less on the dial past 300 yds or so. He suggested it was likely a combination of environmental stuff--temp, humidity, etc--possibly combined with the bullet manufacturer publishing an optimistic BC. I'm not sure how to true this up though so Im interested in what you'll do to correct this.

 

[Stid2677]

You may need to use the Trajectory Calibration (Truing) feature with the StrelokPro app it is the icon on the bottom right. enter the target distance and amount of elevation and calculate. This will give you a corrected velocity based on your drop. Shoot again to proof the data.

 

[luke moffat]

You laser range the target to verify 575?

How’d you check your scope tracking.

Using your numbers in strelok and hornady 4dof I get 3.3 for both based on your numbers.

Lastly why the heck are you running a 7 mag like a lightly loaded 280 Remington

I shoot the same bullet out of my 7 wsm and shot out to 1250 with first round hit on a 18” target using strelok. I am more inclined to think the range is wrong or something with the scope or your shooting some extreme angle.....or your velocity is more inline with what a 7 mag usually shoots a 175 at and 2960 fps which lines up at 2.8 MILs at 575 yards.

 

[itsTyrtruion]

Lastly why the heck are you running a 7 mag like a lightly loaded 280 Remington .

Had quite a bit of 4831sc laying around and the book lists that as close to max... so I loaded up and headed to range.

Had a target with 1cm increments drawn on news print that was about 4.5 feet long. Friend has a rail on a clamp so scope can be pretty solid.

Leica 1600b said 575.

I ran the numbers through a hornady app and bought the applied ballistics app and keep getting different numbers. It’s got to be something with the environmental numbers. To be off by 3/4mil is crazy especially at only 575.



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[luke moffat]

Who makes 5831sc?

I only ask cause I have heard of 4831sc in 7 mag fairly often but no 5381sc as you have typed out twice now. If it’s a powder that I have never heard of (likely) than great. If it’s a matter of transcribing the same number wrong here there is likely others transcribed wrong elsewhere in the app.....BTDT

 

[itsTyrtruion]

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[luke moffat]

Another possibility is if you 100 yard zero is even a half inch high that would make things line up more with what you are seeing.


What scope is it and how did ya test the tracking?

 

[itsTyrtruion]

Another possibility is if you 100 yard zero is even a half inch high that would make things line up more with what you are seeing.


What scope is it and how did ya test the tracking?

Pst gen2 5-25 MRAD
With the centimeter grid of a rail mounted on a block clamped to my buddies truck


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[itsTyrtruion]

Who makes 5831sc?

I only ask cause I have heard of 4831sc in 7 mag fairly often but no 5381sc as you have typed out twice now. If it’s a powder that I have never heard of (likely) than great. If it’s a matter of transcribing the same number wrong here there is likely others transcribed wrong elsewhere in the app.....BTDT

Fat finger typo... and not being able to catch mistake in my own typing


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[Macintosh]

You may need to use the Trajectory Calibration (Truing) feature with the StrelokPro app it is the icon on the bottom right. enter the target distance and amount of elevation and calculate. This will give you a corrected velocity based on your drop. Shoot again to proof the data.

Thanks—wasnt sure how this function was supposed to work, since it seemed to want to increase velocity well above what I had chronographed. Is it sort of a “fudge factor” in this regard? If so isnt it fudging some other factor (environmental?) which would cause me to be off again in the future?