The entire KRISS line is going to be available in .40 S&W later this year. Additionally, lower receivers will be sold so that a .45 model can be converted to .40 S&W. Like the .45 version, it also uses Glock magazines.
The photo below of the prototype .40 S&W submachine gun model. I had to promise them I would make is clear it is a prototype and that the finish on the lower is rough and not what will be seen on the production version.