Have ordered a Stiller 338TAC action for a 338 impLapua build. Jerry was mentioning that an easy way to go on the magazine box, is to use the 378 Weatherby magazine box/bottom metal. Does anyone know how far out I could seat using this magazine box? My other thoughts were to use the HS precision DM which would allow an OAL of 3.670, or the Wyatts DM system. Any suggestions are appreciated.