Field Dope up incline

Pickle Rick said:

So…shot at a new range this weekend 0-600m. Had my velocity and ballistic calculator and all that. Two separate ranges 300m and 600m.

The target at 300m is on an incline. My DOPE said ~1.2 mil. Reality it was 1.9 mil! This took me several shots to figure out. This incline isn’t huge, not like shooting up a mountain or anything but certainly noticeable.

The 600m is pretty flat. My DOPE was right on, within .1 mil of calculator (4 mil).

My thinking was that at level target, drop would be greatest because gravity is acting perpendicular to trajectory of bullet. I guess I was wrong lol this make sense to anyone?

Anyway, first ever shots past 300 yards, at 600m. Not a group, was adjusting holdovers but very exciting for me lol

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Assuming your data isn't corrupt in your calculator the error at 300m is a shooting fundamental issue. Up or down angle will decrease not increase the amount of elevation needed. Plus or minus 20 degrees (which is quite a noticeable angle) is only a -0.2 mil adjustment from the 1.2 mils at 300m for a typical 6.5 Creedmoor.

Pickle Rick said:

So…shot at a new range this weekend 0-600m. Had my velocity and ballistic calculator and all that. Two separate ranges 300m and 600m.

The target at 300m is on an incline. My DOPE said ~1.2 mil. Reality it was 1.9 mil! This took me several shots to figure out. This incline isn’t huge, not like shooting up a mountain or anything but certainly noticeable.

The 600m is pretty flat. My DOPE was right on, within .1 mil of calculator (4 mil).

My thinking was that at level target, drop would be greatest because gravity is acting perpendicular to trajectory of bullet. I guess I was wrong lol this make sense to anyone?

Anyway, first ever shots past 300 yards, at 600m. Not a group, was adjusting holdovers but very exciting for me lol

Click to expand...

Yeah so I with say with about 99.9999% confidence that this shift in POI has nothing to do with the inclination. As pointed out increased inclination always reduces the amount of elevation and in any regards 0.5 mrad shift even in the right direction at 300m out of what I will assume is a high power rifle, would require an absolutely infeasible firing scenario.

More likely than not it a failure of something you think is good but isn’t. Such as fundamentals of body position/sight alignment or improper application/management of data. Given the lack of experience it’s really difficult to story out what your doing wrong with out direction observation.

Things that could help narrow it down might be to show us some more details of your setup.

Rifle
Optic/mount
Ammo

Also what solver are you using and how did you arrive at your inputs such as BC and Muzzle Velocity?

Pickle Rick said:

Magnetospeed chrono. 24” savage 110 in 6.5cm. SWFA scope. Vortex precision matched rings. 20 moa rail. SBC ballistics app.

Maybe I mistook 0.9 mil for 1.9? I remember double checking it though so hmm…

Also, spot on at 600 meters. I’m going again next weekend and will report back if I find anything.

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0.9 mils puts you closer to reality than 1.9 for that distance.

Are both targets completely in the open? No obstructions of vegetation or anything? How is your parallax? Was there a consistent crosswind? Is your reticle level? Is your rifle canted slightly? (1 Degree Cant = .1 Mils every 500M 2.5 Degree Cant = .1 Mils every 200M 5 Degree Cant = .1 Mils every 100M). Do you have a solid and repeatable NPA? So many things could be happening...

As a general rule, as was already stated above, if the angle is less than 30 degrees and the target is 300 yards or less, the shooter will find the difference minimal for practical purposes.

You can completely eliminate the angle of the shot from consideration with just a little math on your end since you [should] have all the data needed.

Standard High Angle Range Correction
Measured Range to Target X Cosine of Angle to Target = Horizontal Distance to Target
Example:
590m w/27 degree angle
The Cosine for 27 degrees is .89 -590 X .89 = 525m
Flat line distance Dial or Hold DOPE for 525 meters

Plug in some of your data and check your shot! Good luck!

*I just realized I am fully resurrecting this post. It was probably solved. My apologies. Everyone