Do I need tin?

[The mood]

Greetings everyone. I stumbled across 185lbs of lead from a machine shop that is 6% antimony but no tin. I am interested in casting plinking bullets for my .40 and 30-06 as well as slugs for my shotgun. My question for you all is whether or not this alloy will work for my purpose or should I add tin? I read the Lyman cast bullets book and searched the forums before posting, please forgive me if this has been discussed before. Thanks

Geoff

[el34]

The strong advice is to have 1-2% tin. It weakens the surface tension of liquid lead so that all mold details fill completely. I blend mine at 2% but never tried non-tin casting. It adds a bit of hardness (0.3 BHN points per %) but that's not the point.

Cool score you found, what's lead doing in a machine shop?

[The mood]

They machine them into small rods that get placed inside long hollow drill bits to help balance them out at high speed. The shop got bought out so the owner sold me all he had left. He thought it was about 100 lbs so I figured fifty bucks was a good price. Got it home and weighed it and it ended up being 185 lbs.

[Beagle333]

Tin makes life better. It just makes it a lot easier to get beautifully filled out boolits with sharp edges on the base and nice crisp lines around the lube grooves, and it really shows its worth if you are a hollow point lover. I like 2% or even 2.5%

[cbrick]

I add 2% Sn to all of my alloy's be it pure or WW. From a metallurgical view you don't want to add more tin than antimony but with a 6% Sb alloy 2% will do nicely. Also, Sn looses it's ability to do what you put it in there to do, reduce the surface tension of the lead alloy past 750 degrees. Sn also oxidizes very rapidly past that temp so you'll need to watch your pot temp, casting at 700 degrees is good.

I have always used pure lead for slugs with 2% Sn added, pretty soft. I've never used a 6% Sb alloy for slugs so I don't know if that would be good or bad or indifferent. Would be good if you'll post your results with slugs and this alloy.

Rick

[Larry Gibson]

For what you want the answer is; yes, you do need to add tin to that alloy.

I suggest you also add 30% pure lead to drop the antimony to around 4%. Then add 2 -3% tin to that. You will then have an excellent malleable alloy with an AC'd BHN of 14 - 17. That will be excellent for your ".40 and 30-06 as well as slugs for my shotgun".

Larry Gibson

[Smoke4320]

For what you want the answer is; yes, you do need to add tin to that alloy.

I suggest you also add 30% pure lead to drop the antimony to around 4%. Then add 2 -3% tin to that. You will then have an excellent malleable alloy with an AC'd BHN of 14 - 17. That will be excellent for your ".40 and 30-06 as well as slugs for my shotgun".

Larry Gibson

Larry
I am fairly new to this centerfire lead alloy casting so far its going really well and getting some impressive results from Powdercoating instead of lubing boolits buts heres my question
Are you saying to use an alloy for shotgun slugs instead of pure lead ?
I just got a lee 1OZ slug mold and its marked pure lead only
so I am asking someone a whole lot more knowledge than me !

[Larry Gibson]

Smoke4320

Are you saying to use an alloy for shotgun slugs instead of pure lead ?

Depends on the "slug" and how fast you push them. I use them in rifled shotgun barrels and push to a pretty HV. The above alloy works very well for practice/zero and will also work well for hunting. I prefer a 20-1 lead-tin alloy for my real hunting slugs.

I just got a lee 1OZ slug mold and its marked pure lead only
so I am asking someone a whole lot more knowledge than me !

That's the slug I use. Pure lead works ok but a bit harder alloy is most often more accurate in rifled barrels when pushed to max safe loads.

Larry Gibson

[bangerjim]

I have played around with 9mm, 38, 40S&W, and 45's with only pure lead. Not fun at all! No complete fill and boolits were not smooth and nice as we all want. Then added about 3-4% pure tin to the pot and the change was amazing. Perfect drops EVEY time. That is on both tumble lube and pan lube versions.

They add tin to solder to make it flow and to slightly alter the melting point to make it easy to use. The tin causes the liquid alloy to easily flow into sweat fittings, electrical connections, and sheetmetal solder work. Try soldering a copper sweat joint with just lead. Not as easy as with 60/40.

Pure tin ingots are pricy. I was lucky to pick up 14# a couple years ago at the price of lead ($0.30 at that time!). They are the long skinney ones like Roto sells.

GO TIN!

bangerjim

[Larry Gibson]

Only takes 3.2 ounces for 10 lbs of all at 2%. One lb of tin does 32 lbs of alloy. Thus the price of tin may seem high but with the results obtained with better quality bullets from the better alloy and less time wasted with rejects it is well worth while to add the tin.

Larry Gibson

[The mood]

Thanks for all of the replies. I got a call this am from the seller, he found another 20 lbs of lead for me so Ill add that to my current stash. My next step will be ordering four or five lbs of tin from rotometals to add when I cast it all into ingots.

[olaf455]

if you exceed $99, shipping from Rotometals is free provided you order online.

[762 shooter]

1-2% tin will make your casting life easier.

762