It's called rifling, and the purpose is to give the projectile a spin in order to stabilize it in flight.
The bore of a barrel is the inside of it.
Cannon with a rifled bore. Rifling is the spiral grooves on the inside of the barrel to cause the projectile to spin. This improved stability in flight and help accuracy
Originally by drawing a cutting tool through the bore that cut one groove at a time. Now it may be done with a rifling button (made of VERY hard metal) that is pulled through the barrel, cutting all the grooves in one pass. Barrels can also be hammer forged- a rod with all of the grooves on it is placed in a heated barrel, and the barrel hammered to shrink it onto the rod- which, when the barrel cools, is removed.
A rifle is a firearm designed to be fired from the shooter's shoulder that has a rifled barrel. A rifled barrel contains spiral grooves within its bore that impart a spin to the fired bullet thus causing it to be more stable and fly accurately.
Yes it could be done, but you would have to locate a smooth bore barrel to change it with. Remember smooth bore barrels are not as accurate as a rifled bore barrel.
Lands
First created in the 1400's, and we do not know who the first gunmaker was that cut grooves into the bore. It seems to be European in origin, and MAY have come out of what is now Germany, but that is really a "best guess".
A Cylinder bore has no choke at all.
When rifled, the rifling tool cuts the GROOVES. Material left between the grooves is the LANDS.
The bore is the inside diameter of the barrel. Simply put, it's the hole down the middle of the barrel.
Bore is the number of lead spheres the diameter of the barrel it would take to equal one pound. Ergo, the larger the bore, the smaller the barrel.
Lands