The actual BC (G1) for the lapua 155gr scenar is not .508 contrary to what most people believe it's .460 (G7 .238) according to lapua's site. The berger 168 VLD actually has a higher BC G1 .473 and G7 of .242. Although some say that due to the 168s design it's flawed to retain stability at 1000yds. But if you could get it running 2800fps i'm sure it would do fine. You might want to go with the 175gr line, as they have pretty high BCs, buck the wind alot better, and retain stability very well at a distance. You might wanna look at the thread i posted about the new Alliant Reloader 2000-MP the guy i quoted was getting 2750fps out of a .308 with a berger 185gr BT LR with a G1 of .553 and a G7 of .283. Which keeps the .308 super sonic to 1200yds
he also had a great extreme spread and standard deviation.
Another thing to really consider is faster is not always better in a sense. The .30 cal range of bullets really doesn't hit their true form till you get to the 190gr+ bullets which is where the good BCs are. I used to be the same way wanted to run a 155gr scenar @ 3000fps, but in reality the difficult part will be judging wind @ 1k and thats where the heavy bullet comes in play. Here's a fantastic article by Brian Litz about the .30 cal bullets. My second signature which comes from this article sums up velocity IMO.
http://www.appliedballisticsllc.com/...rsion.pdfRight
now i'm running a berger 175gr BT LR with 44gr of varget @ 2615fps and it's still retaining 1200fps @ 1000yds. ES 11 SD 4.5. Anyway here is the links.
http://thefiringline.com/forums/showthread.php?t=447510
http://www.lapua.com/en/products/reloading