It depends on what you mean. There is no specific name for a defective firearm other than to say it's defective.
firearm
Generally any given firearm will have the type of cartridge it is desiged to use stampted somewhere on the body of the gun itself.
warranty is: if product is found defective then the product will be repaired within given time period of the warranty. Guarranty is: if product is found defective then the product will be replace with new one within given time period by the guarrantor.
If the firearm owner records the name of the person he wishes to have the firearm and so identifies the firearm in his will, that person is eligible to receive the gun. Otherwise, the estate administrator can indicate who can receive the gun.
A Shipment of 40 tv sets contains 3 defective units. How many ways can a vending company buy five of these units and receive no defective units? The answer I was given was: There are 37c5 ways to get 5 sets with none defective. 37c5= 435,897
Well if you are a boy itcomes out your will nom nom
discrete
It was a brand of firearm. The name was derived by spelling the owner's name- Daniel- backwards.
Her name is Samhita, but she is referred to as "Sam".
gene therapy
Given the tone of the question, I'm going to assume that the firearm is illegally possessed, in which case, you'd be arrested and charged. If your possession of the firearm is legitimate, then you'd have no need for concern, so long as you weren't doing anything illegal with the firearm.
There is no one name, other than perhaps muzzle blast, or gunsmoke.