Sometimes I look at a sprue and a weird idea for a conversion will come to mind; that's how this one came about. Simply put I'm using a knife to make a gun. Ridges on the bottom of the big Catachan knife just struck me as reminiscent of the grips on the hand guard of an assault rifle.
I cut the barrels off of a Catachan las-carbine, then cut the blade to a nice rectangle. Then mash everything back together. Add a scope from your bits box, and there you are.
Hmmm... now maybe Marbo's Pistol?