DA is one number used to represent three different effects:
1. Barometric Pressure: Density of air molecules.
2. Temperature: Speed at which air molecules are moving.
3. Humidity: Amount of water vapor in the air.
Elevation is not an issue, as the effects of that are inherently expressed in barometric pressure.
The thing to understand is that while these effects are interrelated, they are not dependent, and they do not affect your projectile equally. For example:
You can have high atmo pressure with cold temps. (i.e. a calm, sunny, summer day)
You can have low atmo pressure with high temps. (i.e. a summer thunderstorm)
You can also have:
high atmo pressure with high temps. (i.e. a calm, sunny, winter day)
low atmo with cold temps. (i.e. a blizzard)
So you are taking these three different effects and crunching them down to one number. But, you can see the same DA with wide variables. This wouldn't be a loss, except
temperature affects a projectile in different ways than pressure.Using the chart above: (which is hardly precise, but good enough for this demonstration)
Example one: Temp is -18, Baro indicates a pressure altitude* is 8000
Example two: Temp is 43, Baro indicates a pressure altitude* is 3000
*Pressure altitude: To keep from getting to into the weeds on this, think of pressure altitude as just a different way of measuring barometric pressure. Just a different scale, like millibars or inches of mercury.The DA for both of those is approximately 6000 ft. But the conditions are wildly different, and a certain amount of precision is lost because the effects of temp and pressure are not equal.
Now, unless you are a benchrest shooter, the loss in precision is considered negligible compared to the gains in simplicity and speed for field use. In other words: you are interested in more practical long range marksmanship (be it for hunting, tactical, or more practical competitions A.K.A. PRS)
If that is what you are pursuing, then yes,
I highly recommend using density altitude. I just want to make it clear that there is some loss in taking three different factors and condensing them down to one number.
Edit to add: I state that assuming you are not one of the people who will attempt to hump a ballistic calculator in the field. If you are, then feel free to use raw data since it is more precise. (Thats why many calculators still dont have a DA option)
To me, ballistic calculators are just another tool, like my reloading press, or my windmeter, that are great to have and can help you out, but I would never carry in the field (match or otherwise). I instead use small cards graduated for range in 50 yard intervals with both elevation and windage* corrections in mils, with a different card for every 1000 ft of DA.
*using a 10 mph FV base for British method