Same shotgun choke Different barrel lengths will the shotgun spread pattern be, Basically the same ?

[phantom]

Someone ask me this the other day was not sure of the  Answer  if you have Same ammo shotgun choke  but Different barrel lengths  will the shotgun pattern be Basically the same ?  I know  Velocity is  going to be different . But not sure  About pattern spread .  I'm guessing it shouldn't make much of  difference but not sure about that . 

Edited October 15, 2022 by phantom

[Grouse]

Using the same ammo and the same choke, the pattern will be the same if the barrel isn't much shorter.  Dropping a 28 barrel down to 18 inches will greatly affect velocity and could alter the pattern.  The ammo and the choke used are the major factors influencing the pattern.

[mike103]

It takes about 12-13 inches of barrel for the powder in a shotgun shell to fully burn. So barrel length has nothing to do with velocity. Also advertised velocity’s on shotgun shell boxes are off by 100fps most times. 
 

Pattern is determined by choke and/or the wad used. There are wads like Federal flight control that are best used in open chokes that determine pattern density.
 

And there are chokes that hold the wad together to determine pattern and chokes that strip away the wad and deliver the appropriate pattern. 
 

Selecting the right choke is more of a product of what distances you are going to be shooting at or what activity you will be doing such as trap, skeet or sporting clays.

It would help to know what the person will be going with the shotgun.