This is a subject that I've seen discussed here but found an old PM about from an old handgunner so thought I'd elaborate on the subject.
We speak here of cast bullets for revolvers. Bullet size vs bore size vs cylinder throat diameter.
I know Snyd and BFR shooter are some of the experts on this subject and a few others have experience as well. The dimensions of these three do matter from the stand point of accuracy and lead fouling and are important considerations when using hard cast bullets in a revolver. Slugging the bore to obtain accurate bore diameter and cutting the throats to the correct diameter will help when making happy loads.
I like to round up the bullet diameter to slightly greater than bore diameter.
Bore slugged and miked at .4305" I size bullets to .4310".
Cylinder throats will be cut to .4320" or .4330".
(Bullet sizing and throat cutters are usually even thousandths.)
What are your thoughts on these dimensions?