I typically play an A4 with my tuner when I am tuning because that is the note that the violin would be playing.
On the bass, I would be playing the A harmonic on the D-string in fourth position. If I set my tuner to simply record my intonation, the note I play is consistently flatter than 220 Hz, even though it feels in tune against a drone. If I then play the harmonic an octave above that (somewhere F on the D string), that high A is recorded more correctly 440Hz.
I know that pianos and plucked instruments exhibit stretched tunings because of inharmonic strings, but I had thought I read somewhere that bowed instruments have perfectly lined up overtones because of the bow action, but I don't know if this still applies to playing the harmonics themselves.
So what I'm asking is: Is it okay to use harmonics as high as the 6th (5th?) harmonic to tune the instrument? Why or why not? If not, should I tune by ear, playing the lower A harmonic and the A440Hz; or should I train myself to get the tuner to line up to 220Hz?