Greetings! By precision shooting I assume you intend to play around at greater distances. Myself, I shoot a 168gn .308 Win going 2600fps. Thus, I can get away with doping my optic only for range and wind up to about 550 meters. After that, RAW HAT applies...range, angle, wind, humidity, altitude, temperature...all that great stuff. It depends on what caliber you're shooting though. If you plan to shoot at distances that require compensating for environmental conditions, this is what I use and suggest...
KESTREL 3500NV
You can get this at
www.nkhome.com
For Humidity, Altitude, and Temperature, I suggest the KESTREL 3500NV.
It runs for $260, has a dim back-light for when the day starts to fade, is waterproof and floats, takes a CR2032 coin cell battery that lasts 300hrs, and is easy to use. Heck, it only has 3 buttons! Also, it calculates wind which isn't any help for telling the down range wind speed, but it helps you better understand what different wind strengths feel like...so that you can look down range and better estimate based on what you see foliage doing or how fast heat waves are drifting. The difference between the Kestrel 4000 and the 3500 is $80, and the 4000 model logs data...for shooting I don't need to log old data, so I saved the 80 bucks. You may want to keep the data though. You really can't go cheaper than the 3500 model because the 2500 doesn't do humidity, and the 3000 model doesn't do altitude.
RANGEFINDER
LEUPOLD RX III or BUSHNELL ELITE 1500
There is a point (distance) at which mil-dots are not accurate enough, even when you know the precise size in inches of your target. That's the point where a 15 meter error in you range estimation will result in a miss.
Both the Leupold RX III and the Bushnell Elite 1500 are the same price at $400. The Leupold has a feature that you'll need to pay an extra $100 for if you get the Bushnell. The Leupold calculates angle for you. Both are completely waterproof. I'd go with the Leupold if you're not offended by buying a Chinese product. Yes, although Leupold scopes are American they contract their rangefinders through China to be made there...too bad I say, but lots of people don't care.
WHAT ABOUT ANGLE?
So we've covered Range, Wind, Humidity, Altitude, and Temperature calculation. If you ended up choosing the Bushnell Elite 1500 for $400 without the angle calculator you'll need an angle calculator in some environments. A half circle shaped protractor with a weighted string hanging off it is a good cheap-man's solution to digital stuff.
Make sure for precision stuff at a distance you match the length of your bullet to the twist of your barrel to ensure proper long range stability.
So what rig are you shooting and what are you shooting out of it?
Good luck, and good shooting...