Ah . . Not Quite
To reduce the Barrel to Cylinder Gap on a Pietta, one would have to dress back the Arbor, creating the Same Same problem with the Uberti, then Dress Back the Lower end of the Barrel lug to keep the barrel "square" and in line with the chambers. Then re-fit the wedge and . . . . . .
Not worth the effort. I can shoot all month by simply wiping down the Barrel Face when I reload. 5 Seconds. Piffling.
Oh, and bye the bye, the Pietta Arbor isn't "too long." The fitment of the Arbor to the Barrel is correct as is the Bore alignment. Fitting the wedge is du rigger.
Stay Safe Out There