Need Help on How to Map Actual Trajectory with Software

[Full Curl]

LongBomber - I can see how that would give you get data to work with. Just out of curiosity, how do you measure atmospheric conditions like barometric pressure when you shoot?

bigngreen - thank you for all the good points. I'm going to have to shoot again and see what I can determine from there.

 

[LongBomber]

I have both an accurate gps (elevations) and a kestral 4000, plus my rangefinder. Also one of the places I shoot is very close to a governent weather station which I can get data online from, updated on the hour. The same spot is treed on both sides and only open about 10 yards wide which really cuts down the effects of wind. It's my "testing" spot and I can reach out 600yards and be fairly protected from wind. Its really the holy grail of shooting spots.

Most of the bullets I use have the G7 numbers from Litz which do help when you are reverse engineering your settings in a ballistic program. if your rifle is not sub moa capable at the ranges you are shooting trying to revelrse engineer the solution is pretty tough. I started keeping notes on my 300wsm, every time I shoot I record the conditions and what I needed for corrections. Shooting in 5-6 different places in very different conditions and tracking the changes it makes can help you narrow down your trajectory.

 

[engineer40]

LongBomber - I can see how that would give you get data to work with. Just out of curiosity, how do you measure atmospheric conditions like barometric pressure when you shoot?

bigngreen - thank you for all the good points. I'm going to have to shoot again and see what I can determine from there.

If you have an anemometer (like a Kestrel) or watch or smartphone (that uses a built in baro chip not the GPS) or some device that can actually measure your station pressure (where you are), then you don't need to worry about your altitude/elevation or the barometric pressure.

Many devices if you leave your altitude set to 0ft, the pressure it will give you will be your station pressure (which is what you want).

Barometric pressure is used to predict weather events. Don't concern yourself with barometric pressure.

Your bullet doesn't care what your altitude is either. When altitude is used for shooting, it's a guess based on what the air pressure should be at that altitude.

Station pressure is what should be used for ballistics.

Why this gets confusing is because most of the shooting devices that have built in ballistics software, or any application that you are using, almost always includes fields for Altitude and Barometric pressure. Yes, you can use those variables to help. But it's best to leave them blank and just input your real Station pressure. And you find your real Station pressure with one of the devices I mentioned above. Most guys on this site probably use a Kestrel or similar. Although some Android phones and the Iphone 6 have built in Baro chips also.

Hope that helps.