Why the two would not be the same- LOTS of sample to sample deviation in the Jupiters. 1950 J-3's, a real learning curve involved.
At Infinity of the misbehaved lens: if the Focus Ring indicates Infinity, but the RF drives past it, the actual focus is past infinity, AND you are using it with an M-Mount adapter, Put a thin ring in between the lens and the adapter. Or buy some cheap, try them out.
At Infinity of the misbehaved lens: if the Focus Ring indicates Infinity, but the RF drives past it, the actual focus is past infinity, AND you are using it with an M-Mount adapter, Put a thin ring in between the lens and the adapter. Or buy some cheap, try them out.