How is it calculated?

[JLF]

How do you calculate the length of the cast lead bullet to consider when choosing the right mold?

[Winger Ed.]

I don't.
I look for the design/style I want and the weight of it.
Loading data and the overall cartridge length will take care of the rest--- maybe with a little tweaking.

For example:
If I want a .30 caliber Round nose to use in a .30-30--
Look at published loading data for the weight I want, then pick a mold.
Which powder and how much of it is important----- the length of the boolit itself, doesn't really matter.


This is all basically almost 200 year old technology, and what I call 'well plowed ground'.
I try to avoid all the over thinking and hair splitting that is so easy to do.

[Froogal]

The diameter of the bullet and the weight of the bullet determines the length.

[BLAHUT]

The diameter of the bullet and the weight of the bullet determines the length.

Length Also determines what twist rate will stabilize it ??

[JSnover]

Length Also determines what twist rate will stabilize it ??

There's a formula for diameter, length, twist. It helps to know the intended velocity.

[ascast]

I think the Greenhill formula is what you were thinking of. It is an old formula and I believe it has been supplanted by a newer version. They are not 100% It might be quicker and more reliable to just ask specifically here as to what you need to do your job. I would be surprise if someone could help you.

[JLF]

Thank you very much for your help.