Question for using a ballistcs app?

[Runnineh]

Once you get your zero information and save it; is it necessary to rezero another day if you're shooting again? I thought the purpose of saving your zero information was so that all you have to do is upload cureent environmental info and it compensates for that.

I ask because I had a zero set from about a month ago, went shooting in a different area, loaded temp, da, humidity, etc and my solutions were off by up to 1.3 mils.

 

[spamassassin]

Zero should not shift. If it does your gear us busticated somewhere. Otherwise you've given too few details for any kind of helpful diagnosis. If your drops are off by that much then either you're using the app wrong (bad inputs), making serious shooter errors, or your equipment is busted.

 

[seansmd]

If you are zero'ing at 100 yards, verified distance (measured with tape or LRF), and got a solid zero. It should travel well.

 

[Mortalpawn]

I do check zero if I change any equipment, or even change the "lot" of ammo I'm shooting. Normal handling should not change your zero, but if you bang your scope against something accidentally, add a new attachment (which can change how the barrel resonates), tighten down pieces attached to the action or re-torque your scope mount it can sometimes change things (especially if it was not tight in the first place).

Also if you run your gun in the field for several days - well "sh%t" happens and sometimes things will get banged around.

Also I've noticed when I change my ammo from one lot number to another (even for exactly the same ammo) it can shift zero by a click or two. So I've moved to buying ammo in larger lots and I will verify zero when I move to a new lot.

I will say that 1.3 mils is a large change in zero, so I would probably at a minimum re-torque your scope and also make sure nothing else is loose on the gun.

 

[Runnineh]

-Distances were verified by LRF (both 100 and shooting distances)

-Environmentals were collected by kestrel 4500; several times when the solutions were off to make sure I had the the data correct.

- The day i zeroed, i verified with AB from 100-900 yards, the biggest error i got was .1 mil

- SD of my rounds was 9.3 fps for 25 rounds (labradar)

- When got home, I checked the torques of everything except the base and nothing was loose.

I would like to say shooter error, but when I corrected for the indicated drop I was on target.

I feel it would have to be either an error with the kestrel, or im some how not entering the data correctly, but it was pretty much dead on the day I zeroed.

Is there anything else anyone can think of?

 

[Long Range 338]

In a word, truing. Your 100 yard zero shouldn't change enough to be an issue due to atmospheric changes. Once you've entered all of your data (from actual field shooting dope) you make the app match your real world data. AB wants to make this adjustment only adjusting muzzle velocity. Many here adjust BC and MV as part of the truing process. If all of this is correct you have an error somewhere, and it could be anything from data entry to % of error in your optic...

I would make sure to document each range session in a logbook and make the app match your real world data. You may even have to rebuild your ballistic profile using G1 if you are currently using G7 or vice versa. Try a couple of apps, sometimes it could be an update in the app itself. If everything still fails, go back to zero and verify EVERYTHING starting with your equipment.

 

[Steel head]

-Distances were verified by LRF (both 100 and shooting distances)

-Environmentals were collected by kestrel 4500; several times when the solutions were off to make sure I had the the data correct.

- The day i zeroed, i verified with AB from 100-900 yards, the biggest error i got was .1 mil

- SD of my rounds was 9.3 fps for 25 rounds (labradar)

- When got home, I checked the torques of everything except the base and nothing was loose.

I would like to say shooter error, but when I corrected for the indicated drop I was on target.

I feel it would have to be either an error with the kestrel, or im some how not entering the data correctly, but it was pretty much dead on the day I zeroed.

Is there anything else anyone can think of?

An accounted environmental that you didn’t notice?

was it just one rifle that was wacky?

 

[Runnineh]

An accounted environmental that you didn’t notice?

was it just one rifle that was wacky?

That's the only thing I can think, an environmental I didn't think of, but it's pretty much follow the bouncing ball on the app. Once off the rifles eas fine to 500, then a little off after that, the other was off other than its zero.

I think my plan right now iits to go back and recheck the 100-900 again

Thanks for the responses guys

 

[Steel head]

I’ve had situations where things were wonky but it was all rifles.
there’s a steep valley I shoot across for a bit over a mile and sometimes the mild wind you feel and see doesn’t jive with what the bullet is telling you.
Made notes and it’s happened a few times there since.
I now know what to look for at that location.