Rimfire bullet alloy?

[Steelbanger]

I have a chance to pick up a few hundred pounds of 22 rimfire bullets. This comes from indoor bullet traps and is all fragmented into small pieces. What I'm looking for is some softer alloy to blend with my hard metal.
Anyone know the composition of 22's or does it vary from one manufacturer to the next? Thanks.

[felix]

Assume it is all lead, 99 percent anyway. Any boolit that is swaged by a commercial factory will need to be soft in order to make the dies last seemingly forever. ... felix

[Larry Gibson]

As Felix says it is mostly lead. However some has antimony in it. The last batch I got was 1-2 BHN harder than pure lead. It hardens 14-16 BHN when water quenched from the mould thus offering accurate velocities up into the 1600-1800 fps range. Thus hardened the alloy makes excellent hunting bullets as even though "hard" a lead/antimony only alloy is still malleable and does not shatter shatter or break off like a lead/antimony/tin alloy. Of course .22LR lead is usefull for your intended purpose. Definately get it.

Larry Gibson

[Glen]

I think it varies somewhat from manufacturer to manufacturer, but I think it's got about 1-1.5% tin in it to enhance hardness a bit without losing the malleability (important in a swaging process). How much antimony it has, I don't know, but it's not much. My range scrap (which is mostly .22 lead, with a little bit of commercial hardcast thrown in) comes out at a BHN of about 7.5 (air-cooled), and about 13 water quenched. It casts beautifully.

[Hip's Ax]

http://castboolits.gunloads.com/showthread.php?t=6824

[fourarmed]

I have some ingots cast from 100% .22 LR bullets from our club trap. As a project for my physics lab class, I cast some sinkers from it and had the students measure the specific gravity. The ones who did it right got 11.2-11.3. (One got 220!!!) So there can't be much in the way of lighter metals in it.

[Ricochet]

I think 2% antimony's about right.

[Bass Ackward]

Seems we have differing opinions. I say it's as pure lead as the term pure relates to lead.

But let's find out for sure. Heat treat a larger chunk in an oven or water drop a bullet. If it doesn't HT, it's pure. If it does, then we will have to measure hardness to get some idea of what else is in there.

[Ricochet]

Looked up what George Frost said about it in Ammunition Making:

"Antimony content may run from 1% up to 4 or 5%. .22 rimfire bullets from various manufacturers run from 3/4% up to about 2% antimony. 1 3/4% is a reasonable choice. A common core alloy runs 1 1/2% antimony and works well in many bullets. Tin-lead alloy has also been used for .22 rimfire bullets, and does make a good bullet. The percentage of tin needed to equal antimony hardness is about 4-5% tin vs. 1-1 1/2% antimony. Because tin costs much more than antimony, and requires greater quantities of material to get the same result, it is not a good choice for hardening lead alloys."

He'd also addressed above that why pure lead is never used for commercial bullets, except in the dual core arrangement with a nose section of pure soft lead and harder lead in the base.

[georgeld]

That should be dandy for b/p's and hunting slugs that
need to be softer.

For sure get it all.

[Larry Gibson]

I think I said that:-)

Larry Gibson

[Steelbanger]

Thanks for all the replies. Looks like it's just what I'm looking for.

[mag_01]

Good info Ricochet---I'm glad to hear there not pure lead but close to it and should be used as such when determining your application.

[Dan in Wa]

Years ago we picked up about 30lbs. of .22 slugs.
After a few days of drying we smelted them.
A bunch would not melt.....not all are lead.
Just my $.02 worth.
Dan

[fourarmed]

Pure lead has a specific gravity of about 11.3, antimony about 6.7. So an alloy that was 2% antimony by weight would have a SG of about 11.15. That difference probably would not be detectable by the method my students were using.

[Ricochet]

If you quench and age it, it won't be in the pure lead softness range at all. I'm finding that with my soft lead scrap. If I don't add any wheelweights to it, but water drop or oven heat and quench them, they end up being fairly hard boolits. But I can easily nail mark the annealed ingots. Doesn't take much alloying stuff to harden with quenching.