In all old piston types, and most turbopropellor types, and yes, even a very few old CAR4b turbojet types (with certain exceptions)....Vr=V2 in nearly all cases.
Only on later types was it specified by the regulatory certificating authority of the necessary Vr/V2 spread, and yes, on those types, it is mandatory.
Read the book carefully, folks, and do not interpolate un-necessarily, for if you do, there are definite traps for the unwary.