Lyman #49 lists both RN and TC 120 grain cast bullets.
They would be very nearly 125's after the grease groove is filled.
They show 1.065" for the RN and 1.110" for the TC.
But even then, the Lyman bullet molds will probably not be an exact match for the Magma mold bevel-base designs most commercial casters use.
In general, you need to determing the OAL using the barrel out of your gun to chamber check the bullets you have.
Seat just deep enough to clear the rifling and drop fully & freely in the chamber, while also covering all the grease grooves and you should be good to go.
Whatever the OAL turns out to be, is what it is.
rc