The other day I was vectored across the localiser twice without being cleared to intercept it, it was only on the 3rd time that we approached on a closing heading that we were cleared, so at that point we actually armed the approach.
Actually I pressed DCL (decel which arms the LOC, GS and DCL)
On the 139 the guidance is:-
Max recommended LOC intercept angle ............. 45° (range > 10 nm)
Max recommended LOC intercept angle ............. 30° (range < 10 nm)