My oval tubing was formed to be the diameter of the chamber. When you push one in more and more you can feel the beginning of the taper where the chamber may end. The beginning of this taper, as I wrote, measures approx. 2 7/8".

The underside of the left barrel is marked from left to right as follows: + VB/15,8 vbg 8AM.76 112XXX (sn) 20

The left barrel: +++ KGI 220 KMO 20 15,8 PSE HNITO XXV1 173 20

Top of the barrels: ACCIAO-SPECIALE=EXTRA-CANNE CROMATE
V>BERNADELLI-GARDONE V.T. Made in ITALY

The sides of the barrels are marked GAMECOCK and Stoeger Arms Corporation HACKENSACK, NJ

The barrels are 27.5" long choked full and IC.