I’d say there’s a real good chance the gun will work, as in “probably”. Why?1. “Clive” the transporter. Not just a designation, Clive has a real name, a personality, and knows where it comes from. It also was complicit in the murder of other topsiders as well as escaping from them. Plus, Clive has not locked them out of the vehicle even though they are now all mutants.2. Sarah and Jim’s suits – some folks will have noticed when first meeting them that their suits had been “altered” – head antennas missing, etc., suggesting Sarah and/or Jim know how to modify them – or at least sabotage them. Might also suggest they were banished, but then why would Clive listen to them?3. Jim’s Zero gun – was used by Jim to kill other topsiders. While not definitive evidence (we’ve never seen topsiders kill other topsiders before), it suggests modification.