2-3 Weeks. The 8200 Series Field-Corps Bass Drums feature an aluminum arch lug casing 20 percent lighter and 40 percent stronger that uses straight-line technology. The drums are one to two pounds lighter than current models. New 10-ply Birch hoops with a round edge allow pinpoint tension on the hoop, and a new steel wide body caw is designed for today's corps-style tuning, dispersing tension over a larger surface area for more stability.