Lots of good info in some of the posts.
Your gun, not what the manual says, dictates the needed bullet diameter. Throat diameter should match or exceed by .001" that of bore diameter, provided you do not have bore constriction caused by crush fit threading of barrel to frame. If so, that needs to be lapped out.
If needed, you may then need to open cylinder throats to match.
No biggie.
And, this is only worst case scenario, not necessarily your situation.
I'm surprised that nobody has mentioned the case design and neck length of the 22 Jet, both issues which impact cast bullet performance...

BUT..... If your main concern is a steady and economical supply of bullets, you may wish to investigate SWAGING.
There are a few guys making the needed tooling to turn ordinary fired 22LR cases into nice bullet jackets. Then you add your chosen lead core and bullet nose profile. There's maybe 3-4 steps involved, but you end up with a cheap, effective bullet that performs amazingly well at 22 Jet velocities.
The nice thing about swaging, it gives you repeatable and specific bullet diameter, critical when fabricating small bore projectiles, regardless of what method you choose.

Best Regards,
Jim