sure, all it is is an estimate of the bullets path, this info will get you close.
muzzle velocity, published bullets BC, heighth of the center of scope above center of bore, and the exact barometric pressure where you are hunting/shooting.
Now you need a rangefinder, a repeatable scope and a drop chart of some sorts.
Here is what I carry in the field
leica 1200 LRF
pda loaded with exbal (ballistic program)
kestrel 2500 (b/p, temp, alt) if you know bar pressure, alt. is a moot point.
level on the scope
an angle finder (for uphill downhill shots)
a rear support (I use a foam cushion)
so you end up with something like this
Now practice, see where your hitting compared to the ballistic program readings, most of the time you have to tune your chart to your rifle, if you know b/p, muzzle velocity, scope height, the only thing you haven't measured yourself is bullet BC, so how do you fix it?
First shoot at 300,400,500 yards measure your actual drops, are you hi or low? most probably from my experience you'll be high.
This tells you your not dropping as much as your chart says you will, so if like I said before everything is correct, it has to be the wrong BC, so slowly raise the bc of your bullet in your program until your drops match the chart BINGO! now if your on at 300, 400, 500 yards, it just stands to reason you'll be on at 700, 800 and 900 yards.
Once you understand how it works, this isn't that diffacult.
RR