Casting question?

[frosty]

What is the lube for on a hardcast lead bullet?
Is it for helping to seat the bullet?
Is it for helping to keep the bore from leading up?

I have fired and recovered cast bullets still with the lube intact. I can clearly see the rifling marks but almost no lube is gone.

I was wondering why, because a jacketed bullet has no lube.

A plated bullet has no lube either. In fact the manufacturers of plated bullets tell you to load their bullets using only the loads for lead not the fullmetal jacket loads.

What does the lube do for a lead bullet that it could not for a jacketed one?

[inplanotx]

What is the lube for on a hardcast lead bullet?

You answered your question with the second question below it.

I have fired and recovered cast bullets still with the lube intact. I can clearly see the rifling marks but almost no lube is gone.

There are two types of lube. Hard and soft. I prefer the hard, which requires a heated base on the lube sizer. Soft lube melt during the summertime here and can leak into your powder charge.

A plated bullet has no lube either.

The copper PLATE, not jacket, (read that soft metal) is the lube. The jacket on a FMJ bullet is soft and does not require lube. However, you will get copper fouling in your bore rather than lead.

In fact the manufacturers of plated bullets tell you to load their bullets using only the loads for lead not the fullmetal jacket loads.

Because the copper plate is akin to soft lube. It is only a couple of thousandths of an inch thick.

What does the lube do for a lead bullet that it could not for a jacketed one?

Jacketed bullets are not lubed due to the abundance of the soft copper jacket. The lands do not cut completely through a jacketed bullet. They would on a copper plated bullet.

Lube helps keep the bore from leading.

Hope this helps.

Get yourself a copy of the Lyman Cast Bullet Handbook as mentioned in a previous thread.