Introduction

Yes, gun bullets and car engines are the same because both work on the same concept that the expansion of a gas in a container provides some work/power.

History

Thomas Savery first used steam power for industrial use in 1698. The idea of ​​concept is very simple to start with that if we create a pressure difference in a closed container we can gain some power.

So to create a pressure difference in a container at the initial time we use steam to create pressure difference we can burn some fuel like coal to heat water and steam create a pressure difference in a container. But as technology advances, we start burning fuel directly inside the container like petrol to create pressure difference in the container (piston).

How Bullet and Engine work and their similarities.

Nowadays we can burn petrol/diesel inside the container as a result gas expanded and create a pressure difference inside the container for equating the pressure to the atmospheric pressure gas container wants to expand and as a result piston moves and we gain some work and later the convert this linear reciprocating motion into rotational motion.

Similarly, in a bullet, the fuel of the working bullet burns inside the container called the cartridge and creates a large pressure difference which in turn creates a pressure difference inside the container and pushes the bullet out of the gun.

We can't evolve

We do not develop ourselves. We use the same concept of deriving power from the pressure difference in the container. We are improving the technology to get work/power only from pressure difference but now we need to find a new way to get power instead of this pressure difference in the container method.

A better way to get power

We have a better way to get power instead of an engine which is an electric motor. Electric motor is a better technology to get power instead of engine. Nowadays every Indian locomotive uses a 3-phase induction motor instead of an engine. The locomotives which can run on fuel only use their fuel to get electrical energy and then this electrical energy goes to 3-phase induction motor.