Alliant TechSystems Inc., Hopkins, Minn., will begin a manager review now that it has completed an asset allocation study for the $1 billion defined benefit plan, said John Lotzer, director of investments. The new asset mix is 47% U.S. equities, 23% international equities and 30% domestic fixed income. The previous mix was 45% U.S. equities, 25% international equities and 30% domestic fixed income. The manager review is expected to be completed by September. Frank Russell conducted the study.