I helped a friend work out using Sabots in a 12 SxS with rifled screw in chokes. It became quite obvious early-on the gun would not print in the same area, let alone spot, with each barrel, I think I'd have been quite shocked if it had. We tested each barrel to individually with several manufacturers sabots and settled on the Remington Copper Solids in 2 3/4" which are my personal favorites. Set up one barrel with a choke tube for 00 buck and the other for the sabot.
Paul harvested a deer on the opener and I 2 days later (see photo) with my fully rifled Hastings barrel atop my Browning Twelvette which is scoped with a Leupold Vari X III 1.5x5 using the Remington Copper Solid Sabot, have had consistent good sub 3" (many under 2") 5 shot groups out to 100 yards and took this doe at 65 yard with one shot. The shot is a shade high in the photo as she flinched but the angle was such it took out both lungs and was an easy track.
