I'm poking around in the XML files and seeing what options I have in a potential rebalance mod; I thought it would be a fun idea to have the Smoking Gun apply a slow just to it's target. Unfortunately I can't find any way to make that happen, the poison module seems to be hard coded, and I don't see any other option to apply a debuff to the target at least in the Type="MinorModule_Offense" category. 

So I thought I'd post here just out of curiosity, see if anyone has any way to make this work.