because it helps the tanks to move.
A musket is smooth bored, like a shotgun's bore. A rifle has rifling inside the bore (grooves).
Smooth bores are bores or barrels in guns that do not contain rifling. Rifling is made up of lands and grooves that cause the bullet to turn within the barrel of the gun. This turning gives the bullet and gun its accuracy. A smooth bore gun is much less accurate than a rifled bore gun.
No, the Remington 542 rifle does not have a smooth bore; it is a rifle designed with a rifled barrel. This rifling is intended to stabilize the bullet in flight, improving accuracy and range. Smooth bore barrels are typically found in shotguns or firearms designed for firing shot rather than bullets.
The rifling is there to spin the bullet, which gives greater accuracy.
some firearms, like shotguns, have smooth bores. Due to the wide variety of different projectiles a shotgun is expected to shoot (from a fine dust-like shot, to a single, solid chuck of lead called a slug), the best type of bore, in this case would be a smooth bore. With a rifled barrel, you want to shoot ONLY a projectile of a specific diameter. This way, the rifling grooves can grab the projectile and impart a spin to it. With a shotgun, the presence of rifling would only confound things, and likely the rifling would get worn out / damaged by the wide variety of projectiles sent through it.
In the true sense of a cannon (smooth bore) yes. If the field piece has a rifled bore then it is technically a rifle. Modern artillery is primarily composed of large bore rifles. Tanks are an exception to this, their main armament is commonly smooth bore, although more and more are starting to revert back to rifled bores.
Lands
When rifled, the rifling tool cuts the GROOVES. Material left between the grooves is the LANDS.
It would depend on the type of gun,for the most part anything that is called a "rifle" has rifling in the barrel. A musket generally doesn't have rifling and is considered a "smooth bore" There are cases in both instances that cross the line such as rifled muskets (used in the Civil War) and weapons mistakenly called "rifles" as in you will hear a Brown Bess or charliville musket called a rifle. There are also guns called "Fowler's" these are for the most part smooth bore and meant for shot, but can also fire a ball, much the same as the musket.
Direction of spin is dependent on the direction of the rifling on the inside bore of the barrel. A bullet will spin the same direction as the rifling.
Lands
The Thompson submachine gun, commonly known as the "Tommy Gun," did not have a smooth bore; it featured a rifled barrel. The rifling was designed to stabilize the bullets in flight, enhancing accuracy and range. While some firearms with smooth bores exist, such as shotguns, the Thompson was specifically engineered for use with .45 ACP cartridges, requiring a rifled barrel for optimal performance.