Your comment, combined with a comment in ABro's blog, and a remark made by a friend of mine who is a retired police chief detective, is fanning the spark of a thought in my mind. Professional, criminal gang members do care if a gun is clean. It's the amateur gastas who don't care, and who behave dangerously.
According to the police detective, guns can be rented or leased from illegal sources, for a fee, plus a deposit which is refunded when the gun is returned. The guns are clean. If the gun is used in a crime, it can't be returned but must be destroyed. I don't know all the details of such a transaction, but you can bet that care is taken so that the gun can't be traced to the supplier.
The comment from ABro's blog is related to this: "[Joseph Michael Horth aka Spiken Mike] ... testified at the prelim that a guy called John Low had given him the AK-47 as collateral for a small loan and that he had tried to destroy it with a hammer. When that failed he hid it in the crawl space under the house where he was living in Mississauga. Police raided the house and found the gun in January 2014." From the article: Crown asks for review of Justice Antonio Di Zio ruling in Matthew Ward-Jackson case
http://www.annrbrocklehurst.com/tag/matthew-ward-jackson
"Collateral for a small loan?" Does that sound like a deposit?
There are a few questions that linger in my mind. What did MS mean when he said that he'd f'd up? To whom was he referring when he said that he was afraid "they were out to get him", or "they don't don't mess around". I forget his exact wording. Surely he was not afraid of the Bosma family. Why was MS in such a state about getting rid of the gun? Why did he so stubbornly refuse to say where it is? Is it possible that the gun was rented and now, having been used in a crime, had to be paid for and destroyed? When MS needed money so desperately, was it really in order to hire a lawyer?