Stock , Barrel & Action
non expanding bullets, Expanding bullets, and Frangible
It is rare to find a modern firearm (last 50 years or so) that has NO markings at all. It is possible that those markings may have been removed from a modern firearm. Without some additional information, such as the type of firearm, we do not have enough information to offer a real answer.
Rifles, shotguns and pistols are the three main categories of firearms. A modern firearm consists of three main components: Actions that load, unload, and eject ammunition.
The simplest would be a single shot muzzle loading firearm. In modern cartridge firearms, a break action firearm. They are made as rifles, shotguns and pistols.
Any firearm using modern cartridges can be. However, it is an extremely dangerous thing to do with any firearm, and this should not be attempted.
Can't be answered until you define what "modern rifle" means.
If it's a modern .30-06 rifle, yes.
None of them are modern. They have been around for hundreds of years. Lock, Stock and Barrel
Nothing, really.
The receiver is the frame of a firearm- in modern firearms, it is the part that the barrel connects to. Antique firearms, such as muzzle loading rifles, did not have a receiver- only the lock, stock, and barrel. (Yes, that is where the expression came from) On a modern firearm, if it has a serial number, it is stamped on the receiver. By US law, a receiver IS a firearm- everything else is parts.
Flintlock or cannon type weaponry.
There are many more than 2.