No
Type of rifling/twist.
science, Bullet markings and check them with the rifling of the firearm. Barrel twist and or markings can help ID the gun fired from. Nothing can tell you for sure, It can just tell you it was fired from a barrel like that of a type or make.
No, but, they are able to use forensics to tell if a weapon fired a projecitle if they have an example.
When a gun fires, the primer and burning gunpowder eject residue. That residue is chemically like very few things OTHER than gunshot residue (GSR) If your clothes test positive for GSR, it is a pretty safe bet you were very close to a gun that was fired. It may or may not tell whether YOU fired the gun.
A round is loaded into a gun. The gun is then cocked and then fired.
This gun is a Rifle
A gun recoils when fired due to the need to eject the casing and to recycle the pent up gas
It doesn't.
A machine gun uses energy from the fired cartridge to operate the mechanism to unload the fired catridge, and to load a fresh cartridge- which is fired, and repeats the cycle.
it is very difficult considering the barrel could have been replaced but usely there is some wear on the inside
When a gun is fired a bullet (or cartridge) with a small mass but a very high velocity is ejected. The recoil of the gun is a reaction to this force and is sufficient to push back the person who fired the weapon.