What does adding tin to Wheel Weight alloy do?

[Black Jaque Janaviac]

So far I've been using straight wheel weight alloy to do my casting.  I've had no problems with the bullets filling out the mold.  Well, if I do it always seems to be due to a cool mold or a poorly ventillated mold.

So I don't need tin for mold fill-out reasons.

What I'm looking for is something to make my cast bullet hold together better instead of just shattering to pieces on impact. 

I thought maybe softening the mixture by adding pure lead might do the trick.  And perhaps it will.  But I'm thinking that adding tin, as expensive as it may be, might be cheaper than adding pure lead.  Sure pure lead is cheaper, but I only need to add 1 or 2% tin compared to 50% Pb.

Will the extra tin harden the wheel weights much?

As far as a source for tin.  I'm thinking I might scope out garage sales that might have a cheap beer stine or two - maybe $0.25 each.  I recall reading somewhere that the little flapper lids are made of tin.  They are certainly soft.

[Nobade]

Extra tin will lower the surface tension of the metal, and allow it to flow better. If you need the bullets to be softer than air cooled wheelweights, lead will help or even better use just lead and tin. A bullet cast of 1:20 tin/lead won't shatter, and will expand when it hits.

I had a similar problem with wheelweight bullets shattering on silhouette targets and not knocking them down. I was water quenching them for hardness. I quit doing that and let them air cool, and they were soft enough to hold together long enough to knock the rams down. I was pretty impressed at the difference that change made.

[Bitterroot Bob]

Howdy,
Wheelweights have a fairly high antimony content, but very little tin. Antimony requires tin in order to alloy with the lead. Without tin, the antimony exists in the bullet as crystals throughout the lead. I add a couple feet of lead-free solder to the wheelweights whenever I add weights to the pot.
One pound of lead-free solder (95% tin and 5% antimony) to 19 pounds of wheel weights equals 20 pounds of Lyman #2 alloy.

Bitterroot

[jhalcott]

  blackjack , what velocities are you shooting these frangible bullets? Sounds kind of like my linotype slugs.

[Black Jaque Janaviac]

JHAlcott,

Anywhere from 900 fps to 2400 fps.

900 fps is .38 spl from a handgun.  I guess if I want expansion with those I will just have to cast with pure lead. 

I have a number of .357 loads that run anywhere from 1200 fps to 1900 fps depending on the amount of powder and whether I'm shooting from a revolver or rifle.

And of course, I have a .35 Whelen that I use to shoot paper patched  280 grain slugs.

For the most part.  If I'm shooting .38 spl loads, I only want the bullet to bump up or obturate enough to seal the bore and give me good accuracy.  Mushrooming and cohesion are not a real big factor.

It wasn't until I started shooting the paper-patched Whelen that I began to wonder about things like weight retention, and holding together when colliding with bone.  The 280 grain slug mushroomed nicely passing through one gallon water jug.  But they lost about 90 grains of lead.  I'm sure it would be worse if it were hitting elk bone.

[ron haralson]

Mostly, the result of adding tin to wheelweight metal is to give you more uniform bullet weight and a little less leading. another way of saying better fill - out and better alloying.

If you're going to harden your bullets it's important to use less tin than antimony.

If you are happy with your consistency, you might not bother with the tin. It's expensive.

[Black Jaque Janaviac]

Without tin, the antimony exists in the bullet as crystals throughout the lead.

This might be worth the experiment then.  It seems that the .35 Whelen bullet expand, then breaks off.  Maybe if the bullet was a consistent malleable metal instead of a conglomeration of "crystals" it would hold together better. 

[WILDCATT]

IF IT BREAKS IN BIG PIECES IT WORKS BETTER. 1% TO 2% TIN IS ALL YOU NEED.I.VE USED PLAIN WW FOR 38 TARGET FOR 30 YRS OR MORE IT FLATTENS ON THE BACK STOP.I USE SAME IN RIFLE AT 1600FS WORKS FINE.MY SON JUST KILLED A DEER WITH SKS WITH HARD BALL.DROPPED IN ITS TRACKS.YOU YOUNGSTERS WORRY TO MUCH.

[jgalar]

Adding tin makes my bullets look prettier, but I can't see that they shoot any better. Plain WW is what I mostly use for rifle and pistol.

[Black Jaque Janaviac]

Wildcat,

You have a point there, and I haven't totally dismissed it.

I mean, heck, I'm starting out with 280 grains of lead.  If it dropped down to 140 grains I'd still have the equivalent of a .270 bullet.

I guess in some respects this was a dumb question since there's no reason why I couldn't simply try it out and see for myself.  Tin is expensive, but not THAT expensive that I couldn't add a few feet of wire to a lead pot and make a run of bullets to try.

[R.M.]

I'd be tempted to try watering down your WW say 50/50 with soft lead, then add a bit of tin to help it fill out. 

R.M.

[BABore]

I don't use or have the need for any tin. Fillout is good with controlling the mold temperature and not allowing overheating. I've been cutting my WW's with Pb 50/50. I sort all the WW's and keep the soft stick-ons seperate, treating them as pure lead. An alloy of 50% WW's and 50% Pb cuts the antimony to 1 1/2 to 2%. In an AC state the bullets are 9-10 Bhn. The alloy has enough antimony and arsenic left to still harden. Either WD or OHT bullets run 18-22 Bhn. It's also malleable enough, even heat treated, to expand some without riveting. The mushroom or petals will still sometimes shear off, but they're pretty good sized.

I just ran some wet newspaper expansion tests using a 300 gr HP out of my 375 H&H. The media was at 50 yards and my MZ velocity was approx. 2,400 fps. Penetration was 21 inches deep. The first 8 inches of wound cavity was 3 inches in diameter. The mushroom fragged off into the second grocery bag of wet paper. Evidentily this bag was a little on the dry side where the bullets went through. Retained weight was only 100 grains. Some of this is due to the HP cavity depth which I'm going to shorten up some. The test rounds cavity depth was approx. 0.400 inches deep.

Another plus for this alloy is it eliminates the grey antimonial wash you get in the barrel at high velocity. I began to notice this when I started getting above 2,000 fps with straight OHTWW's. The lube wasn't giving up (LBT Blue), and I wasn't getting leading in the traditional sense. Just a powdery grey coating. I've compared a 50/50 alloy against straight WW's, both soft and hard, and the 50/50 wins most every time in the accuracy dept. I pretty much shoot this in all my guns, whether handgun or rifle.