The only problems with rifle grenades is that they are heavy, inaccurate and tie up the rifle from which they're fired. Due to those shortfalls, they are disappearing from inventories and rightly so. A 40mm under a rifle is a far better solution.

Whether the XM-25 is going to be a plus for combat -- heavy combat -- remains to be seen. For combat operations like the current efforts, it does what it's supposed to do -- which is more than can say for most of the tripod or vehicle mounted AGLs. Those things are significantly overrated. Though they are fun to play with...

Last I heard, Canada proposed to replace their 60mm mortars with 40 AGLs. I hope, for their sake, that's not true...