Small changes in length have little effect. Large changes have more effect. Longer barrels in hunting shotguns are used to control the swing of the gun while tracking birds rather than effective range considerations.
Depends on what gauge, what load and barrel length
Yes, the length of a shotgun barrel can affect the distance of the shot to some extent. A longer barrel typically allows for a more consistent and tighter shot pattern, which can result in slightly longer effective range compared to a shorter barrel. However, other factors such as the type of ammunition used and choke selection also play significant roles in determining the effective range of a shotgun.
From the breech.
From the breech
There is no restriction on barrel length but the overall length of the firearm must be 26.5 in or greater
18"
That would depend on the make and model of the shotgun in question,and the length of the barrel/barrels that came with the shotgun.
A shotgun barrel length or rifle barrel length starts at the point where the rim of the case touches the shoulder of the chamber and extends to the tip of the muzzle. In most cases, if the barrel is threaded on, yes it would include the threads. lcj
If you mean the legal length of the barrel? it is 18 inches and for rifles it is 16 inches.
A little over 36"
18" for shotguns
It will vay depending on the model and when made.