Depends on what gauge, type of use (hunt, compete, home defense), etc.
Not recommended
Being a double barrel has no bearing on what the choke COULD be. While MOST are full/ modified. it could be any, or none. Shotgun ChokeYardageShotgun Choke Restriction Diameter difference between bore and shotgun chokeCylinder< 200Skeet22.5.005 of an inchImproved Cylinder25.010Light Modified30.015Modified32.5.020Improved Modified35.025Light Full37.5.030Full40 or More.035Extra Full40 or More.040
A barrel with a full choke.
System of changable shotgun choke tubes made by Mossberg. Accu Choke is their brand name. A shotgun choke is a means of reducing the bore size at the muzzle of a shotgun, to produce shot patterns that spread to a greater or lesser degree.
Cylinder bore- no choke at all.
It is possible to fire a shotgun without a choke, but it is highly not reccomended, and they don't cost that much If you select a barrel with no choke (cylinder) it will cause the pattern to be looser than for a barrel of a shotgun that has a tighter choke. The extreme is "full choke" which keeps a tight pattern out to the effective range. Full choke is typically used for waterfowl. A shotgun that is pressed into double duty (shot for small game and slugs for big game) would work well to have modified choke. Slugs have to be designed to fire through a full choke without blowing the barrel but you will certainly shorten the life of the barrel by firing slugs through a choked barrel. If you can afford an extra barrel, then use a cylinder (no choke) for slugs. Remington and other shotgun manufacturers have interchangeable choke tubes (see link) that allow you to screw in the appropriate choke for your quarry.
A pattern of a shotgun is determined by the choke at the factory. Some models have a variable choke that makes the user able to change the pattern.
http://www.gunshop.com/dgsnos3.htm
They came in various barrel lengths and choke combinations. If it is not marked on the side of the barrel, you will have to pattern the shotgun to determine the choke
A shotgun barrel with a cylinder bore choke.
Yes- that is what the poly-choke is for.
Question refers to a double barrel shotgun manufactured by H S B & Co of Chicago. It was a Genuine Damascus brand with a Choke Bore (not borel). Good Luck