Help Figuring out Ratios of Alloys to Mix

[Z.F.Bowles]

I’ve got 15lbs of 33% tin lead alloy. I’ve got a bunch of clip on wheel weights also, how much should I mix to get a useable alloy? My bullets are still coming out wrinkled with the tin/lead mix. I don’t believe I’m going too slow or anything. PID set at 700. Have I mixed 15lbs of trash or is too much tin possible and I just need to cut it with coww? Thanks.

[garandsrus]

Take one pound of your alloy and mix it with 10 lbs of pure lead and you will end up with about 3% tin, which should be fine. You could add 15 lbs of pure and end up with about 2% tin, which would work well also.

[RickinTN]

You have plenty of tin for sure. Much more than I ever use. Your problem is probably that your mold isn't hot enough, giving the wrinkled bullets.
Rick

[Dave W.]

I have found that cutting clip on wheel weights with pure lead in a ratio of 2 lbs COWW to 1 lb Pure lead works well in most pistol loads, but it needs some tin added. So mix one pound of your alloy with 30 Lbs of COWW and 14 pounds of pure lead, should work ok. If you are shooting rifle bullets or high speed pistol loads, this mix may be too soft.

[georgerkahn]

Good morning, happy Boxing Day (the day after Xmas ) and welcome to the Forum!
After several decades of bullet casting, I continue to loudly voice my ineptness at any approach towards perfection in alloys I end up. My number one challenge is NOT knowing what the alloys -- not pure metals -- I start out with are exactly composed from?
Your wrinkled bullets may be from not-pristine-clean moulds; from temperature still too cool (I have brass mould which cast almost-perfect bullets approaching 800*), and/or the dreaded contaminants in your alloy. To wit, COWW may have, or be made of zinc -- a metal most do NOT want any of in their bullet casting alloy.
Definitely not the brightest bulb in the fixture, when I get wrinkled bullets I first raise my pot's temperature; then, I FLUX, FLUX, and re-flux that which is in my pot. I use pine sawdust, (Gouda and Edam) red cheese-covering wax... and -- if these do not do the trick -- some MarVeLux. If this doesn't work, I re-wash/degrease moulds with Brakleen spray after a good Dawn and hot water with old toothbrush wash. [] SERIOUS WARNING: Do not, under any circumstance, permit even one drop of water/moisture near/in your pot -- specially noted if you do wash your mould -- MAKE SURE IT IS 101% DRY!!! []
To my experience, if *I* want sharper, shiner, clearer-cut boolits, I add tin to mix. If I want harder bullets, I add a product sold by RotoMetals called "superhard".
RE YOUR CHALLENGE: I'd raise the temperature up to whatever to get FROSTED bullets. When the bullets get frosty-looking, they are still (imho) quite suitable for shooting -- and if the wrinkles disappear you solved your challenge. (You can slowly lower temp until you get shiny, still wrinkle-free bullets). If they are still wrinkled -- I'd do some serious alloy fluxing.
A good "read" on alloying is on a wonderful site -- the Los Angeles Silhouette Club -- on web which has lots and lots of GREAT info -- as well as a marvelous BOOK on bullet casting by guru Glenn Fryxel. Notable, germane to your query, therein is an article you may wish to read at http://www.lasc.us/CastBulletAlloy.htm .
BEST wishes!
geo

[Land Owner]

No doubt about it...georgerkahn an makes excellent argument for the unknown components in an alloy and the inability to make EXACT predictions. The pure math - if you had pure components - looks like the image below.

ASSUME you are using pure components in the mixtures apportioned below and go forth and cast.

Assure your SPRU PLATE is HOT-Hot-hot before you pour your mold. Heated mold components help to diminish wrinkles.






This is Math and I approve this message.