M2 particles can possess momentum but are not affected by gravity and so don't show up as weight. When similar poles are pointed towards each other, the particles collide in perfectly elastic collisions, giving rise to repulsive forces. Consideration of the distortion of lines of forces reveals this, irrespective of which pair of like poles are facing each other. Unlike poles are attracted because the lines of force are now deflected away from the centre region to the ends of the bars. Put simply, a lowering of M2 pressure occurs in the middle, whilst extra lines are produced at the extremities.
Forces are a consequence of any change in direction of the particles, just as with any fluid flow.
No resultant force is exerted on a bar magnet because M2 does not react with M1, our standard mass dimension. M2 possesses inertial mass but not gravitational. Therefore a piece of matter known to contain M2, should not obey Newtons laws. There should be a difference in G, for instance, between iron or copper and manetized iron. Whether or not iron contains M2 intrinsically or not can be revealed by comparing iron with magetised iron.