How much tin?

[keebo52]

For 35 years I've poured straight WW boolits for pistol. Now I'm starting to cast some rifle stuff. What % of tin do I need to get the molds to fill better?

[johnly]

I like to cast 10:1, but that's because I have about 100 pounds of solder stashed away. 20:1 casts almost as well as 10:1

John

[docone31]

I fire up my Lee 20lb pot, crank up the heat, add maybe 2" of 95/5 solder, really heat my mold, and cast away. The hotter the mold gets, the fewer wrinkles are visible.
My rifles though don't care about wrinkles. They all shoot just as well for me.
I paper patch my castings. Any imperfections in the driving portion of the casting is gonzo before wrapping. I don't care about rounded lube lands, rounded bottom, it sizes out. The paper acts like a gas check, I think. Once I got my sizing down pat, they outshoot my jacketeds.

[Springfield]

It's not all about the tin. I can cast perfect 44-40 bullets with pure lead. I usually use a mix of 50-1 just to make them a bit harder. With the proper heat anything will fill out.

[grouch]

I use 2% tin to wheelweights. An old friend uses 1% with good results. In a straight lead?tin mix, 20:1 works well for me.
Good luck.

[Gunslinger]

I believe 2-5% is what most people do. I've read that more than 5% is a waste, as tin doesn't really harden the alloy that much, and the bullets don't get any more shiny. Have never added more han 5% tops, so I'm not speaking from experience...

[keebo52]

I just scored 3 - 5 gal buckets of 60/40 waste solder from a radiator shop. It's full of crap but I can clean it up. So 2-3 % tin is sufficient?

[Shuz]

FWIW--I've been using wheel weights plus 1% tin for years with good results for a handgun alloy. Personally, I think any higher percentage of tin is a waste of money.

[Larry Gibson]

I also use 2% tin with the newer, softer WWs ( still lament for old WWs and only have 2/3 of a 5 gallon bucket left). New WWs with 2% tin is good up through 1800 fps second or so in rifles for general target and practice. Works well faster for hunting loads. For an alloy comparable to #2 alloy I mix new WWs 60/40 with lead.

Larry Gibson

[Tom Herman]

I don't yet cast rifle bullets, but 2% Tin is what I use in my revolver bullets. Works well for me.

Happy Shootin'! -Tom

[MakeMineA10mm]

You'll probably get almost as many answers as there are people here. I've cast 100s of thousands of pistol boolits (most with a Ballisti-cast machine, but I've hand-casted for 30 years too), but only a very few rifle boolits.

I was involved in a thread here that a fellow was doing some pretty scientific work on hardness. He found (and it is backed up by some pretty scientifically detailed articles in the Lyman casting & reloading manuals) that boolit hardness is closely associated with the formation of a compound of tin and antimony in the boolit metal.

Basically, if you start with wheelweight metal, that usually has between 3 and 4 percent antimony, you add tin to get the hardness you want. For pistols 2% will get you plenty of hardness for most pistol loading. For rifles, 3-4% will get you the hardness you need for rifles - combined with GCs, you can go over 2000fps, if your rifle's bore is agreeable. For low-velocity loads, it's probably best to add pure lead to the WWs to get the boolits soft enough to obturate.

As far as how much tin you need to get your boolits to fill out (must be casting some Loverins? :mrgreen: ), 2-3% along with a reasonable pot temperature and casting tempo should get you fully filled-out boolits. To get good results with rifle velocities you want that much tin anyway.

The book on commercial casting by Paul Moore says that any more than 2% tin is monetarily wasteful as far as pistol boolits are concerned, because that's all the tin that's necessary to guarantee good fill-out.

According to the principle of the tin-antimony compound creating boolit hardness, I'd say with WWs as the base for your alloy, anything more than 3.5% is a waste. WW+3% tin is what I'm going to use when I start casting rifle boolits.

[Bret4207]

Clean your mould and turn the heat up. I cast mostly rifle boolits, but it doesn't matter it it's a 90 gr 6.5 PB or a 250+ gr 35 cal boolit I use straight WW. Maybe mine are older than yours, but I very rarely have fill out issues if the boolits are coming out slightly frosty. I bought a bar of tin from Midway years ago and still have over 75% of it left. Try turning the heat up and cast faster.

[Andy_P]

I've always believed that Tin does very little to increase hardness, that its purpose is to improve fill-out. Antimony (as found in WW) does a lot to increase hardness, and especially so when heat-treating or quenching, as it is the active ingredient in the hardening. As many others, I add 2% Tin to my WW, and water quench if I need it harder than about BHN 13.

[Gohon]

If one goes by the writings of Rick Kelter over on lasc, wheel weights have a hardness of 10-12 BHN but when cut with 10% 50/50 bar solder that hardness jumps to the same hardness as Lyman # 2 which is 15 BHN. That's a 20% increase in hardness.

[grumpy one]

If one goes by the writings of Rick Kelter over on lasc, wheel weights have a hardness of 10-12 BHN but when cut with 10% 50/50 bar solder that hardness jumps to the same hardness as Lyman # 2 which is 15 BHN. That's a 20% increase in hardness.

First, in my experience WW average 10.5-10.8 BHN air cooled, but if you raise the tin a bit, to 2% tin and 4% antimony the hardness increases to an average of 12.2 BHN. Second, I find an alloy with 4% tin and 3% antimony averages 14.5 BHN, and one with 8% tin and 7% antimony averages 17.8 BHN. (I know, sloppy alloying, I over-ran on the tin in both cases. Tin should never exceed antimony if you use both.) So, the numbers you have quoted are pretty accurate, but the Lyman #2 should be more 16 than 15.

Tin does tend to contribute to air-cooled hardness if antimony is also present, and both elements are in moderate doses, but the relationships are quite convoluted. Frances Weaver published a chart in 1935 showing BHN for each combination of tin and antimony in a lead matrix, up to a maximum of 14% tin and 24% antimony. Her chart has been posted on this board at least twice, so you should be able to find it. If you can't, let me know and I'll post it yet again in this thread.

[trk]

You've seen a LOT of good info. I'll hit an extreme - I'm casting 96.5% tin 3% silver 0.5% copper - because I have well over 100 lbs of it. If I get good accuracy ho-hum; but if I get excellent accuracy I'll let y'all know fast!

[Gohon]

So, the numbers you have quoted are pretty accurate, but the Lyman #2 should be more 16 than 15.

I think you're right and now that I reflect back about it, I believe the write up said 15 BHN which is close or about the same as Lyman #2.

[yarro]

2% or more tin should improve fill out. Wheel weights get their hardness from arsenic and antimony. If you cast too hot the tin will oxidize out before anything else.

-Yarro

[Gohon]

The only role arsenic plays is to act as a catalyst for the antimony.

[mroliver77]

You've seen a LOT of good info. I'll hit an extreme - I'm casting 96.5% tin 3% silver 0.5% copper - because I have well over 100 lbs of it. If I get good accuracy ho-hum; but if I get excellent accuracy I'll let y'all know fast!

Your casting boolits outa this? Man could I stretch this a long ways. I cast some boolits outs "pure" tin when cleaning and making ingots once. Man were they pretty! I couldnt bring myself to shoot any. Willbird tells about his Pa melting and shooting up a large hunk of tin back in the day not knowing what it was.
Jay

[odoh]

Dat masked stranger howling in the distance, known to some as Kemo Sabe calls dem 'Silver' bullets.