Well that's a ruined batch

[jonk]

I had been sitting on an old ammo box from some Bulgarian 8X56R ammo for awhile. I had heard it was tin and figured I'd use it for alloying. Well, it melted ok... seemed to melt a little harder than tin usually does, but it did melt, in my Lee pot. But it didn't 'just' melt. I had to help it with a propane torch. Which, given the low melting point of tin, made me quite suspicious. Poured it out into small ingots.

Ignoring the signs that this wasn't tin, I tried to alloy it with lead today. No go. Hard to melt and when it did, it didn't really want to blend in- not like alloying tin at all.

Not sure if this was zinc or aluminum or an alloy of the two, but it was useless to me. Fortunately I only ruined about 4 pounds of lead.

Anyone know for sure what this stuff was, that is, what they used for the spam can type ammo boxes in the 40s in bulgaria? Long shot, but worth asking.

[Artful]

I think the East Comblock used both Zinc and Tin/Lead Solder - sounds like you got Zinc

[jonk]

Well this was pre-eastern bloc, but it makes sense... proably used the same tooling and equipment as they had during the war.

My experience with zinc is that a tiny bit in a mix is ok, but this is enough that it's beyond use... might remelt one piece and use my casting thermometer to figure out just what it is.

[jonk]

To update this: After pouring out the offending metal, I melted 5 lb of pure lead in the pot. Just what was clinging to the pot made pouring impossible, from a lyman ladle. Repeat. Same deal. Getting wise and not wanting to waste more pure lead, I used some wheelweights. Keep in mind this is the third full pot, with fluxing, scraping with a spoon, and emptying since the mystery metal. Bullets were still a little wrinkled and had poor fill out, but at least it was pouring again.

I've never seen zinc be this aggravating to get out of a pot, I'm really leaning towards aluminum, or an alloy of some sort. God knows what.

[Walter Laich]

even when I knew I had a batch of zinc it cleaned up nicely when I emptied the pot and did a through cleaning.

I agree you must have gotten into something else

good luck

[mozeppa]

wasn't aluminum fer sure...that melts a 2000 degrees.

[JonB_in_Glencoe]

Last year I did a hardness comparison test with a alloy with precisely 1% zinc added.
My thought process was...I was told zinc will act as a hardener to a lead alloy, and if kept below 2%, it won't effect pour-ability.

The bottom line was, I did get an increase of hardness about 1 to 2 points.

Now to the point, I had slush issues on top of the melt during the test. After trying to cleanup and empty the pot, I noticed the same slush with the next pot of alloy, and then the third pot of alloy as well. Finally during casting with the fourth pot of alloy, the melt started acting like it should. I'm not sure where that trace amount of Zinc hides? but it was hiding somewhere. I was told Tin and Zinc like each other...meaning it helps to have 2% or 3% tin in the alloy for blending Zinc...or cleaning/removing Zinc contamination from the pot.

[jonk]

Last year I did a hardness comparison test with a alloy with precisely 1% zinc added.
My thought process was...I was told zinc will act as a hardener to a lead alloy, and if kept below 2%, it won't effect pour-ability.

The bottom line was, I did get an increase of hardness about 1 to 2 points.

Now to the point, I had slush issues on top of the melt during the test. After trying to cleanup and empty the pot, I noticed the same slush with the next pot of alloy, and then the third pot of alloy as well. Finally during casting with the fourth pot of alloy, the melt started acting like it should. I'm not sure where that trace amount of Zinc hides? but it was hiding somewhere. I was told Tin and Zinc like each other...meaning it helps to have 2% or 3% tin in the alloy for blending Zinc...or cleaning/removing Zinc contamination from the pot.

Very interesting. I continued on and it was indeed the fourth pot that began acting normal...

[Artful]

wasn't aluminum fer sure...that melts a 2000 degrees.

depending upon alloy as low as 1200 F