Assumed Position: adjustment necessary when using calculator?

[Stearmandriver]

I don't know the answer to your question but maybe you could take several sightings and figure them both ways. if your results are close you might have your answer.

Yup, that occurred to me after I wrote this.  I've tried plotting 2 sightings reduced by tables and the resulting LOPs are less than .2nm away from the ones the calculator returned, so I'd say the calculator is running its calculations using the actual AP.  It seems the modification in the tables (249) is to absorb the error from rounding LHA to a whole degree value? So I suppose, if you're doing the actual trig (the way a calculator does), there's no need to round. I suppose, also, this makes the calculators results a little more accurate than the tables... but if we're talking two tenths of a mile, I'm not gonna be too concerned.

Thanks!