Yes, as is, Ty's brass inserts fit into DW barrels just fine. SP barrels and DW barrels(thanks for the info Ty!) both use orings to center the insert, even if it's tolerances are off like some of the SP inserts.
If you are using the brass inserts, even the PPS ones, in barrels thaT have been milled for inserts(and don't use orings) it may require a tad bit of sanding. But even sanded to fit these types of barrels, my inserts still fit both my cocker and phantom threaded DW barrels.