Sinclair 6.5mm insert which measures .250. I don't have a lot of factory 140eldm ammo around, but none of it come close to 2.190. Maybe I need a new set of calipers!
I'm no expert but my TL3 with a PVA barrel and a 140 eld I'm hitting the lands at about 2.184. But you measurement on the Hornandy factory ammo sounds incorrect, after measuring several, all mine come in around 2.127 to 2.130.