How much tin do you need?

[DirtyChris]

Hi I'm new to this whole casting thing, still in the process of getting everything together and reading up on the forums here. I've gotten a stash of some lead, and had some questions about the best way to alloy what I have, or what else I need to come up with.

I'm going to be casting solely for 38 spl/357 mag black powder loads, for Cowboy Action Shooting, so I'm looking for a pretty soft alloy. But I hear you need some tin to help mold fill out and cast better bullets.

What I have: 18 lbs pure lead. 15 lbs SOWW ingots. 30 lbs range lead. and about 13 lbs of "hardball" alloy (old 9mm bullets from Missouri Bullets that I don't need anymore)

The alloy calculator shows all this mixed would be .46% tin, 1.42% Antimony, 98.1% lead, with a BHN of 10.

If I left out the pure lead it would be .6% tin, 1.86% antimony, 97.5% lead, 10.5 BHN.

Would either of these mixes cast good black powder bullets, or what would you suggest for what I have so far? Get some tin to mix in with it and leave out the hardball alloy?

Thanks!

[digger44]

If I left out the pure lead it would be .6% tin, 1.86% antimony, 97.5% lead, 10.5 BHN.

I would shoot this ^^^^^ with another .5% tin added.

[gofastman]

If I left out the pure lead it would be .6% tin, 1.86% antimony, 97.5% lead, 10.5 BHN.

I would shoot this ^^^^^ with another .5% tin added.
I would add the pure lead to soften things up a bit, 10BHN is actually pretty hard. Go to the thrift store and look for some Pewter dishes, or you could go to the hardware store and get a roll of high % tin solder.
you could also order it from Rotometals.com

[cbrick]

DirtyChris, welcome to CastBoolits,

I'm not a balck powder shooter but yes, tin (Sn)will help with mold fillout as long as the pot temp stays under 750 degrees. The general rule of thumb is no more Sn than the percentage of antimony.

Most black powder shooters use a pure or nearly pure lead with maybe a little (2%) Sn. Most cowboy loads are pretty mild also so you probably wouldn't need to mix all that together. I would save the range lead and hardball for better uses. The alloy calculator coming up with those numbers would depend entirely on what alloy you entered for the range lead and range lead can be quite a mix of everything.

Rick

[popper]

I agree with cbrinck except I'd try the COWW without any tin first, see how they cast & shoot. You can WD for a little harder CB. Cast some from each without mixing to see how each shoots, sweeten the best one with the HB if needed. That would keep your limited supply 'known' without ending up with a lot of some funky alloy. I'd work on dropping good casts without tin - so you're shooting CB action - you don't need 'pretty' BCs. Tin is barely stronger than lead so it doesn't add anything but fillout.

[DirtyChris]

Thanks for the replies. I think what I'll do is leave out the hardball alloy, and use the pure lead and stick-on WW to soften up the range lead, and get some solder to add a little more tin.

[runfiverun]

good idea.