I have a set of Brownng Citori 28 inch fixed choke vent rib barrels that fit my 525 20ga 32" clays gun, I need to send them to Briley, to get them bored out and cut for screw in chokes. You need to remove the current choke to put in a screw in choke. Briley is the Gold Standard for high end shotgun work. Comes back done right.
Thank you, you reminded me, those barrels are on my barrel rack, bhind another pair of barrels.

“To expect defeat is nine-tenths of defeat itself. It becomes a self-fulfilling prophecy. It is best to plan for all eventualities then believe in success, and only cross the failure bridge if you come to it."
Francis Marion - The Swamp Fox