Barretts are not noted for match accuracty. Primarily for engaging vehicles.
Second you may find that 50 cal centerfires are not legal in many states to hunt with. Check your game laws.
For the ultra long range, you probably want a 338 Lapua Ack Improved or the 338/416 Rigby variat. Both with 34" barrels will put a 300 gr bullet out there at 3000-3200 FPS.
Loading for 50 cal is very expensive $5-10 per round and all different presses dies etc.
The above cartridges can be loaded on standard equip. Gun can be built for either for roughly $3000 depending on components versus $5000 for match grade 50 cal. Big part is scope that has enough elevation and accurate lr rangefinders like the Barrs and Stroud or Wilde that go 16 miles.
Go to Dan Liljas website www.liljarifles.com
and read his articles on lr hunting with these type guns, rangefinders, dropcharts etc before you go any further.
[ 05-03-2004: Message edited by: BountyHunter ]