Snipers will take a lot of effort to achieve a more accurate shot. This has led to the use of portable ballistic computers. But there is also a ballistic computer in a wristwatch (along with a digital compass and all the usual digital watch features.) This is the "5.11 Field Ops Watch" (costing about $240). While a bit bulky, it works, and the battery lasts for over a year, even with heavy use. Hunters are the main market, but snipers have found it useful. It means one less thing for snipers to carry. Snipers usually travel light.
Last year, the U.S. Army and Marine Corps began issuing handheld ballistic computers. The 17 ounce Trimble PDA type device is loaded with Horus Vision targeting software. This enables shooter to more effectively hit targets over 2,000 meters distant. The $2,000 device is dust and waterproof, and uses rechargeable battery AA batteries. The devise also has Blue Tooth and WiFi, as well as a speaker and microphone. The software handles things like weapon model, target speed and range estimation, wind speeds and many other factors. Shooters can also add, and store, data particular to their weapon, or several weapons (and recall the data for the one you are using.)
The marines have ordered 1152, and the army 6500. Many snipers have already bought their own systems. One popular one is CheyTac, which is a commercial PDA with CheyTac ballistic software. This works with the Kestrel 4000 wind/temperature/atmospheric pressure sensors, linked to the PDA. This system provides that extra bit of data needed to hit man sized targets at 2,000 meters or more. The CheyTac works with most electronic and non-electronic scopes.
A cheaper solution uses an iPhone and iPod Touch (which looks like the iPhone, but is just an iPod with a big screen and wi-fi capability). BulletFlight software is available at the iPhone software store, and it performs the calculations needed to account for atmospheric conditions (wind, temperature, humidity, altitude and barometric pressure) for long range shooting. The output tells you how many clicks to adjust your scope to make the shot more accurately. Before use, you input basic data like rifle type and bullet weight.
Now a highly experienced sniper can do this in his head. There are similar dedicated devices that cost about $7,000. But BulletFlight is affordable, does the job and appeals to inexperienced snipers, hunters, recreational shooters and those who are just curious. The software costs $12. If you want to actually use it, you need to buy a protective case ($50) for the iPod, and a device ($25) that attaches it to the rail found on most sniper rifles and high end hunting rifles. So for shooting purposes, the entire kit costs you about $90. An iPod Touch (8 gigabyte version) sells for under $150.
There is some concern that the light from the iPod Touch screen might give away the snipers position at night. But you can set the light level on the Touch, so it probably won't be a problem. Besides, you are using BulletFlight (or the competing iSnipe) for long range shots (300 meters or more), so the light from the display won't be a major risk.
IPods are popular with the troops. Not just for the music and videos, but also for foreign language translations. This uses special software developed for the U.S. Army and distributed to troops in Iraq and Afghanistan. Soldiers and marines are big users of smart phones (like the iPhone) and new ideas. A lot of troops have tried out BulletFlight, even if they aren't snipers.
The "5.11 Field Ops Watch" uses SureShot software, which operates pretty much like the other systems described above.