Mitch did used to have an assault rifle, the idea being that it was the result of fitting his automatic pistol with some attachments to convert it into an assault rifle. This idea was dropped as it still fired pistol ammunition, which wouldn't have made it any more effective as a rifle weapon. Also, it would have meant that Mitch's primary weapons would be a pistol, sword and assault rifle, which was the same loadout of Peter Edgewood and I didn't want the two characters to have identical weapon types.
However Mitch really did need an upgrade to his arsenal, so I got designing. Not long after some basic concepting, I came across a YouTube video from the Forgotten Weapons channel about the H&K SL-8. I found it interesting as it bore a resemblance to what I had already been designing, so I used it for further inspiration. To make it more useful against armour, I added the RPG launching section.
I'm quite happy with the current design - it's one of the better looking weapons I've come up with in my opinion. A little bigger than I would have liked, but you can't really slap an RPG launcher onto a rifle and expect it to remain titchy. And yes, I do realise placing the rifle barrel significantly lower than the sights may make it trickier to line up accurate shots.