Dakota, Were you not around when the 470R was brought over from Tribune to run on your cornheads in the October time frameIJ That machine, ie R-series 2002 vintage would have had the new wire type rotor grates that have the ripple or flutter effect for greater separation. If you want more separation out of the old style grates, then rotate their position, like car tires, so that there is an "abrupt curb" edge to each slot instead of the worn "ramp" effect. This will cause more grain to drop through the grates, instead of the tendancy to skip over the grate holes and create what you have descibed as the "rifle effect". Frankly, the bi-rotor technology allows the holes to move with the crop, which gives grain more opportunity to pass through the grates, while also experiencing greater centrifugal force. This allows the bi-rotor concave to utilize smaller grate holes because of their relative motion in the same direction a crop flow. A subsequent benefit is that this also prevents larger MOG material from passing through and overloading the shoe. That is where the next big advancement in separation will occur in order to get more class 8 and 9 capacity within the small machine package.