Bill Harriman cleans up the problem.
I own a three-shot semi-automatic on my shotgun certificate. My brother owns the same model and make of semi-automatic, but it is a five-shot and it’s on his firearm certificate. The only difference between the guns is my magazine has been restricted to two cartridges by a gunsmith.
My brother wants to bring the gun to my house without the barrel so that I can strip it and put the damper/piston assembly, plus the firing pin assembly, into my ultrasonic bath to clean them. He wants to leave it with me — the stock, magazine, firing pin assembly and damper — so can I legally have these parts in my possession with only a shotgun certificate under the 72-hour rule? I also have a firearm certificate, but the shotgun is not listed on it.
As your brother’s gun is subject to section 1 (and held on his certificate), only he and registered firearm dealers may possess it or any relevant component part of it. The law defines relevant component parts as: a barrel, chamber or cylinder; a frame, body or receiver; and a breech block, bolt or other mechanism for containing the pressure of discharge at the rear of a chamber.
In law, a relevant component part of a section 1 firearm is also treated as if it were a complete firearm and needs specific authority to possess it. There is no legal bar to your brother bringing the shotgun to your home to use your ultrasound cleaner.
However, it would not be lawful for your brother to leave any relevant component part at your home. The parts that you list do not come under the definition of relevant components, so your brother can leave them in your possession if he wishes.