Both the Pardner® Turkey Gun and Pardner® Waterfowl
come in 10 gauge and 12 gauge. They use the same receiver on both gauges so the chamber diameter of both the 10 ga and 12 ga barrels are the same. So rechambering the 12 ga barrel to 10 ga is quite easy.
What I'm wondering is if there is enough wall thickness to have the 12 gauge barrel bored out and rifled to 10 gauge? There might be enough metal in the walls to remove the .036" needed to go from the .729" smooth to a .775" groove diameter bore. There wouldn't be much more metal removed than when backboring.