I have for sale one set of MX8 29.5,O/U barrels. stepped, tapered rib type four. Three choke tubes. I.C., Mod. and I.M. Briley S1 flush thin wall chokes. 18.4 bore. The rib is 7x11mm. The barrels have a Hi-Viz site. Bottom barrel is ported by Briley. I bought the barrels two weeks ago. It shoots too high for me. I also believe the side ribs have been worked on. They appear to be tight. The barrels shoot well but like i said i prefer something 50/50, these barrels are more like 80/20 high. These are good solid barrels. just not for me. I am selling and losing money but i would rather find something else. Slight dimple on the left barrel side two inches below the muzzle. Does not show or go into the bore.