The industry standard paintball size is .68 caliber. However, the standard barrel bore is .689. If you are looking for a barrel that will fit the paintball, overbore, because paintballs are sensitive to heat and moisture and they will swell up throughout the day.
cleans the barrel
no, because the air is what pushes the paintball out off the barrel.
The diameter
Any autococker threaded barrel.
All paint ball guns with a regular barrel will shoot around 300 feet. there also is no specific "ak 47" paintball gun
you need Co2 to fire any paintball gun, it is what physically moves the ball out of the barrel.
Buy better paint, and get a barrel that fits the paint well. Also clean your gun often.
The bore of a gun relates to the diameter of the hole in the barrel - and in turn the diameter of the bullet the gun can fire.
Two piece barrels allow you to change the diameter of the bore, which lets you fit the paintball better, leading to more accuracy.
AIM B Style Red Dot Gun Sight-wrong your barrel
Yes, it is what physically moves the ball out of the barrel.
It shoots semi automatic and has a removable feedneck and barrel.