Pistol, revolver, rifle, gun. If you mean the device which holds rounds of ammunition, that would be a magazine. If you mean the parts of a firearms "round" you have 4 parts. Primer,casing,powder,bullet.
I believe you are referring to "cartridge." The cartridge is the entire assembly of the bullet, primer, powder charge, and casing.
A firearm is basically a gun; a device designed to fire a bullet. A weapon can be anything. If I use a pencil to poke you in the eye, the pencil becomes a weapon.
It depends on what you mean. I'm guessing you mean the magazine, but the answer could also be: the case, the chamber, or a couple of other things.
A FET is called a square-law device because of the relationship of ID to the square of a term containing VGS.
It would be classed as a destructive device, not a firearm.
A device that allows you to compensate for bullet drop
Extractor
In general, it is not so much a matter of "figuring it out" as it is measuring it. A device called a chronograph actually measures the speed of a bullet in flight. Based on that speed, and a figure called the ballistic coefficent, you can then predict approximately the speed, drop, and energy at various distances.
Sight
What is the drawing device containing graphite.A pencil.
The EJECTOR. The EXTRACTOR withdraws the empty case from the chamber, but the EJECTOR throws it out of the firearm.
If it's an NFA tax stamped device or firearm, yes. If it's a typical Title I firearm (your 'everyday' sort of gun), no.