Sight In Atmosphere Question

[6point5x284]

I have two questions relating to atmospheric conditions when sighting in pertaining to applied ballistics, and many other ballistic programs.

1) Powder Temperature: Is this nothing more than the temperature your bullets are at the time of sighting in? If I sight in and it's 65 degrees farenheit, is that my powder temp as long as bullets have had enough time outside where they are the same temp?

2) Zero Atmosphere: It says in the applied ballistics program and others, that I don't need to input my zero range atmosphere for a 100 yard zero. This wasn't making sense to me. Not saying it's wrong, just need help understanding it. Wouldn't you want at least your density altitude and temperature recorded somehow when you zero? What if I zero at 10,000 feet at 100 yards, but hunt the next month for coastal blacktails at 500 feet? I realize my 100 yard shot would see minimal movement, but I zeroed at 10,000 ASL feet and never had temp or density altitude entered/stored for my zero conditions, and then take a 850 yard shot on a coastal blacktail at 500 feet ASL (hypothetical...the brush is so thick 50 yards is a stretch!) won't that cause POI shift? Obviously, the density altitude and temp for the current shot are input, but with no baseline how does it know how to tell me to adjust?

Like I said, I'm not trying to say the program is wrong, those guys are crazy smart. I just need help understanding how it doesn't effect it later on in hunting season. I usually do loadup in the summer at 100 degrees, and hunt Montana at 20 degrees. I'm just worried I'll have impact change unless I record my zero atmospherics somehow. Thanks for any help!

-6point5x284

 

[406precision]

Powder temp is simply the temp that your powder was when you collected or verified your velocity.

For all intensive purposes we leave that with a zero input as it is very hard to determine exactly what that figure should be.

The zero atmosphere is an option that allows you to enter aNY zero number and have the program auto calculate changes to your zero based on current atmospheric conditions compared to those from when you zeroed. The reason they claim this is not necessary is that the minute changes that occur at 100 yards based on these environmental differences are so small that they are very hard to evaluate between shooter error and a calculation diffrence.

No matter what you do always take the time to zero your rifle or moving to an area that is way different than where you zeroed.

These programs base all calculations off of a true zero if you fail to verify your zero then it's garbage in and garbage out.

Jordan@406

 

[jonthomps]

Powder temp is simply the temp that your powder was when you collected or verified your velocity.

For all intensive purposes we leave that with a zero input as it is very hard to determine exactly what that figure should be.

The zero atmosphere is an option that allows you to enter aNY zero number and have the program auto calculate changes to your zero based on current atmospheric conditions compared to those from when you zeroed. The reason they claim this is not necessary is that the minute changes that occur at 100 yards based on these environmental differences are so small that they are very hard to evaluate between shooter error and a calculation diffrence.

No matter what you do always take the time to zero your rifle or moving to an area that is way different than where you zeroed.

These programs base all calculations off of a true zero if you fail to verify your zero then it's garbage in and garbage out.

Jordan@406

^^^^ This.