User blog:ShowFanNeville/M6 Bushnell variants

I have found specifications for the M6A2 Bushnell, the M6A3 Dark Bushnell, and the M6A2E2 Bushmaster, but the M6A2 and the M6A3 both have additional equipment, giving them roughly equal weight and performance. Does anyone know where I can find specifications for the M6 and the M6A1?