Here ya go Ed...
The .338 is fairly new to the sniper community, but it does bear the distinction as being the first and only caliber designed specifically for sniping. While this round was actually developed back in 1983, it wasn't until the last few years that it has gained in popularity. The caliber was designed to arrive at 1000 meters with enough energy to penetrate 5 layers of military body armor and still make the kill. The effective range of this caliber is about 1 mile (1600meters) and in the right shooting conditions, it could come very close to the 2000 meter mark, provided you have the right rifle/ammo/optics/shooter/spotter combination. Realistically, 1200 meters is well within the average sniper. This caliber is designed primarily as a military extreme range anti-personnel round, there really is no Law Enforcement applications, unless you need a super penetrating round for either armored vehicles, or for barricaded suspects. There is not a lot of rifles chambered for the .338, but the list is growing with the likes of Sako, AI, and others producing .338 sniping rifles. Ammo is another problem, match ammo is sometimes difficult to find, but it is becomming more available as time passes. We all know the legal liability of using hand loads, so that is out of the question. Another concern is the recoil of this caliber, even with a good muzzle brake, its brisk. So don't try a rifle without one. Be sure to practice the fundamentals of shooting to try and prevent a flinch from developing.
Recommendations: For military extreme long-range anti-personnel purposes, the .338 Lapua is king. Even the .50BMG falls short (Do to accuracy problems with current ammo). This caliber is not recommended for Law Enforcement.