If it helps any, here is my set-up for the 408's we build in-house:
Stiller's TAC-408 receiver
1:14 29" PACNOR barrel (no brake installed)
Timney R700 bottom safety trigger
Baer Customs' DBM/Mag
McMillan A5 "wide body" stock (lug bedded)
419gr projectile (LeHigh or CheyTac)
505 Gibbs...