No, I' m not saying it' s bad to mix shot sizes! I don' t know!! If Remington can do it, I suppose it' s O.K. The main thing I heard about mixing sizes is that, because of the difference in ballistic coefficients of different size shot, the shot string tends to lengthen abnormally, and the different sizes pass the target at very different times from one another!! So, even though the patterning board seems to show a good, solid pattern, that there really are as lot of holes in the pattern depending on time!