I was looking for some easy Autocannons for my
CSM. Hacking up the Defilers' Reaper Autocannon would be a major PITA. Big Shootas from
AOBR actually look the part! Here's what I came up with:
It's not a straight swap, because you need to hack up the support arm (I recommend bending the hand downward) and snip a few pieces off of the
AOBR big shoota arms so that they fit properly, but all in all it's a hell of a lot easier (and cheaper) than buying or converting real Autocannons.
You could spend a few minutes
De-Orkifying the thing...in that case the only indication that it's an Ork arm is the gargantuan hand. Most people probably won't notice that the little skull is an Ork glyph-style skull rather than a grimdark regular.