I'm thinking about doing this. Where can I get a .50 bmg bullet mold ?

There are several firms that make moulds.  NEI (Northeast Industrial) use to have a mold that pretty much made a bullet that looked like a jacketed projectile.  Most of the other bullets you can cast do not look that way.  I think that casting characteristics for it are in a 2010 Gun Digest article on bullet casting.

Anyway getting 40 bullets an hour is about maximum unless you have more than one mold because a bullet that big takes a very long time to cool.  Also the visual acceptance rate is horrible.  Still with a single shot gun they work.  How accurate they are I just do not remember.

But I am about to buy another 50 BMG so eventually I will figure that out, again.

Hope this helps.

P.S.  When I did shoot cast bullets in one of these, a Barrett 99, I cut the recommended powder charge in half.  You could tell when the bullet landed because the hill literally moved.

I agree.  But it is a cheap way to shoot one and, well, shooting a 50 a lot is a lot better than not, I think.

No luck with the cast so far.  Tried gas checked version and different lubes/coatings.  Easier to just shoot some regular ball/ap projos.  I stocked up a few years ago for well under $1 each delivered.  There are still good deals out there, it just takes patience and a little luck.

I know this is an old post, but NOE makes a 50bmg mold. It is 850+gr bullet. Just depends on your alloy at that size to get a closer weight estimate for you.

Greg