If you read some boxes of jacketed bullets, you'll find that the diameter is .4515 usually on Hornady.
I think my casting blocks drop a bullet at least .454 and I never worry.
If you mike out an older Colt Python, you'll find that their bore narrowed towards the muzzle. I've seen some at .354 and shot jacketed rounds without over-pressure signs.
For lead or lino, I like to be a tad over myself, like shooting .430 or .431 in an SW .44 Rem Mag. Of course, that being said, I size mine to .429 and shoot just fine.
I think this is more of a problem with older revolvers, usually old .45 Colts where the chamber diameters were wildly different than the barrel specs. If a tad larger, it swaged into the forcing cone. If smaller, it just slid on the rifling.