I too have had trouble with 125 Zeros in the 9mm. The problem is while this is a very good bullet but it has a very sharp corner between the base and the side of the bullet. This combined with the dies in the square deal B that have a very short carbide insert that sizes the the brass so that it has straight sides almost to the base and then a short taper to the case head causes the bullet when seated to not center itself in the case but to bulge the case on one side. Bullets that have more of a radius on the corner help some but it still happens. I spoke to Dillion on this and they stated that that is the way the dies are designed. Since then I have switched to a 550B and Redding Comp. Pro dies. These dies have a much longer carbide insert and do a much better job of sizing the case and seating the bullet straight and eliminated the problem.