Uh.....
.6293 ?
Nominal bore diameter of a 44 Magnum is .429....
Presuming a typo....
What you want to check is the bore diameter, also. You want the bore diameter to be a little less (.0003 less would be fine) than the cylinder throats. You do not want the bore to be bigger, as the bullet may not fill out the bore and the rifling may not engage the bullet properly.
As to the diameter of jacketed bullet, the manufacturers make 44 caliber bullets normally .429". Someone makes one in .430" but I can'r remember who. If you are going to make your own jacketed bullets, make them to fit the chamber throat, or a thousandth over.
It really doesn't matter, as when the round goes off, it will upset and fill out the cylinder throat. In effect, it gets resized. Then when the bullet gets into the rifling, the ogive of the bullet slows down, but the base is still accelerating, so it again is resized to fit the bore.
It's almost as complicated as Congress.