Gentlemen,
I have 2 double rifles in 500bpe that like the Cast Performance (.511) 350gr hard cast bullets. My buddy has an unlimited supply of Meister hard cast lead in his private indoor shooting range. He casts his own .577bpe bullets from it.
My question is: What weight of bullet mold do I need to make 350gr hard cast bullets. Arn't bullet molds listed based on the weight of pure lead bullet they will make?
Is there a formula for comparing Hard Cast-vs-Pure Lead weight?
Thanks, ND

Nitrodave--Even if your bullets are off several grains from intended weight, with 350 grain bullets it would have to be a very large amount to be very much of a percentage. Even if not 350 grains, what difference will that make? Buy a mold, cast some bullets with that free alloy and get them to group. You want be parting a gnats hair and a few grains wont matter.

Carpetman,
Thanks for the reply.
Bullet weight is critical to barrel regulation in double rifles. I can adjust powder for 5-10 grains difference in bullet weight. Much more than that and regulation goes to hell.
Does the alloy mix not change the weight much?
Thanks, ND

If anything your free alloy will cast a few grains heavy. Try them and if you need lighter add tin if heavier is needed add pure. lead Clint

Nitrodave--Not ever having a double, I have no experience with regulating. The nearest I can think of was having a Savage 24V combo gun where one barrel was .222 and the other 20 guage. I did put a 1x-4x scope on it, but had no luck getting the scope set to be accurate for both. Maybe you could lube your bullets with Ex-Lax and get things regulated?

Ha-Ha!
I did some math based on the 502gr .585 bullets my friend is making with this alloy. Looks like a custom mold at 358gr .511 should throw slugs around 350gr, with the Meister alloy.
I love this stuff! We shot 2 Russian boars with our .450bpe's, using Meister Hard Cast 300gr. Shot up the tail pipe, and the taxidermist dug the slugs out of both pigs skulls. They weighed 360 and 420 pounds.
Thanks, ND

I have a Lyman .457 535gn mould that with wheel weights drops a 537gn bullet, with a soft nearly pure lead makes a 546gn bullet.

so roughly:
Bullet weight in pure lead * .9835 = Bullet weight in wheel weights. (546 grain * .9835 = 537)

Or:
Bullet weight in wheel weights / .9835 = Bullet weight in pure lead .

FWIW