Stevens vent rib double 20 gauge

[Highknob]

I have a set of Stevens 20 gauge vent rib barrels. I suppose they are for a 311 but I can't tell. Two beads both white. The rib is dove tailed front and a screw at the rear. 24 inch and measure .605 and .615. Anyone have any info??

[Bobups]

All the details should be stamped on the top of the left barrel That is where Savage/ Stevens puts the info.