[Kangspec]

i searched here and there. but still confusing.

i see lots of HD shotguns have (Fixed Cyl / CYLINDER BORE)

Is fixed cyl barrel or cylinder bore able to shoot Rifled Slug safely?

[faizi]

Yes,it can fire safely.

[Virginian]

You can safely shoot a rifled slug thru any choke constriction. The only way to find out which is the most accurate on your gun is to try it. Usually more open is good, but I have seen a modified choke shoot them like a rifle.

[Jack2427]

The Ithaca Deerslayers, and Police Specials that were provided to the military in the late 60s in VN were mostly full choked. When Ithaca provided trhe Chicago PD with thousands of police guns in the early 70s they were also full choked.
+++ for the above answer, the only way to find out is to shoot the slugs through various chokes, or various slugs through one choke. I have an old 1901 Winchester 97 with a 30 inch full choke barrel, it shoots Brenneke slugs like a rifle out to about 75 yards, other "rifled slugs" it sprays like a garden hose. With smoothbores and slugs it is a very different game than with a rifled bore and sabot rounds-they are more like a rifle round and can be predictable from shot to shot.

[Deltaboy]

Full Choked kick like a mule!

[Old Guard Dog]

One of the only barrels I know of that you CAN'T shoot slugs through is the Mossberg 835 Unti-Mag overbored barrel. It is stamped right on the barrel.