Add tin?

[DocSavage]

Been casting a long time but I'm a bit stumped here,I have a some alloy that's 97% lead and 3% antimony and wondering if I should add any tin as I'm not sure how well defined a bullet a tin less alloy makes. Uses of the alloy rifle and pistol.

[BK7saum]

Are you hunting with this alloy or just target shooting? I personally would add tin no matter what, but tin allows the bullet to flow upon impact and not shatter

[wwmartin]

I've been casting with isotope lead for about 3 years which is 97.5 /2.5 no tin from what I can find on the internet. It casts nice bullets as is. But have always wondered if adding tin would improve them.
How much tin is the question. The BHN now is as hard as I want 10.5 and have not had a problem with leading. Casting weight on the last batch ran from 209.7gr~210.4gr for 260 bullets in that session. I don't hunt just shoot paper.
Bill

[DocSavage]

Not a hunter punching holes in paper for the most part but on the other hand don't want to be scrapeing lead from my bore either. Rifle molds are gas check which is another concern. Want the shank to fill out enough to hold the gas check when the bullet is sized/lubed.
So the actual question is how much tin,1%,2% I have some 50/50 lead lino and bought tin solder to add to what I have now.

[popper]

I cast for rifle and pistol, don't use tin. It is expensive and unless really required - why bother? I do see a use for casting with pure to get decent fillout. Some appear to use it to get expansion, IMHO it is just so the mould fills well when using pure. I did use some when I cast pure + zinc so the fillout was good.

[kevin c]

My understanding is that tin up to 2% is used to improve fill out, but so does raising alloy and mold temp. I use it because I have it and because my aluminum molds run faster, better and longer at a lower temp range than what I think a tin less alloy might need.

My application is target pistol in volume. As a paper puncher who coats the casts, I don't worry so much about hardness and expansion so I'll let the wiser heads with the experience comment on that.

[Conditor22]

I like to cast between 690 and 720° the hotter you cast the more the boolits shrink when cool (test it does improve fill out)
if I don't get the fill out I want I'll throw in .5 to 1 oz of tin/pewter (I cast all my pewter into .5 oz boolits)

as previously mentioned, tin improves fill out and lets you cast at lower temperatures which can speed up casting and give you larger boolits.

[bangerjim]

I put 2% Sn in everything, because I have hundreds of pounds of it. It is rather expensive.

Sn lowers the surface tension of the melt, helping "stubborn" molds fill out better.

2% is just my standard in my casting soup. It may not be required for many casting situations. Try leaving it out and see how your boolits turn out. This hobby is about experimentation!

[P Flados]

It may not be required for many casting situations. Try leaving it out and see how your boolits turn out. This hobby is about experimentation!

I agree with the above.

I have a stash of tin but only dip into it on very rare occasions.

Instead I first play around with pot temp and mold temp (time between drops) to try to get good boolits.

Since my targets are pretty much paper and steel, I have never have to worry about terminal performance.

I do feel that alloy choices can make a difference for some of my more demanding applications. However, the vast majority of my loads would probably work fine with any boolits 1 or 2 BHN harder than pure.

Lead, hard lead (for blending) and tin are all getting more costly and/or scarce. That said, if you are hurting for lead there is a good chance that what you find at a local scrap yard will on any given day be pure or real soft.

I have been trying to save back my stash of tin and harder lead just so that I will have some if I find I need it.

[Bazoo]

I add tin to wheel weights. 1%-2%, as little as I can run and get too fillout. It's the difference from 50/50 keepers to 80/20 or dare I say 90/10+. When the pots good and my mould is in the temperature zone I have cast in the high 90s percentage wise. I try for perfect fillout.

I find lee TL moulds do well without tin vs RCBS or Lyman.

I've tried many varying techniques, so far what works best is, ladle casting, 3/4-1" freefall, about a nickel sized single sprue that doesn't overflow the edges or into the next cavity.

[white eagle]

try you alloy in your mold
if it doesn't fill out and is wrinkled
then ad tin you may not need it

[GregLaROCHE]

Try your alloy first. Make sure the mold is completely free of any oils and warmed up. Be sure you have adequate flow rate. Finally raise the alloy temp until you start getting frosting. It you haven’t gotten the type of fill you want, then start adding some tin. Somewhere I heard casting only lead and antimony together is harder than pure lead to get good fill. That is why tin is usually added.

[Larry Gibson]

Not a hunter punching holes in paper for the most part but on the other hand don't want to be scrapeing lead from my bore either. Rifle molds are gas check which is another concern. Want the shank to fill out enough to hold the gas check when the bullet is sized/lubed.
So the actual question is how much tin,1%,2% I have some 50/50 lead lino and bought tin solder to add to what I have now.

Adding 3% tin will give you a very good ternary alloy. The equal parts of tin and antimony will combine forming the sub metal SnSB with will, when fluxed, stay in solution in the lead. It will cast excellent bullets. All in all and excellent alloy.

[Drm50]

I add 20:1 Tin. I’ve been casting for better than 50yrs and guys tell me I’m wasting tin. I might be but my bullets come out with well defined sharp edges on grease grooves. I hate rounded off edges on bullets that some alloys and molds tend to make. Not a product of temperature. I have a antique mold that was my grandfathers when he was a kid. Buffalo Bill Wild West figures, like tin soldiers. There is Indians with head dress, bows and arrows, cowboys with lasso. This is were Tin really shows you about flow. You would never get the fine detail to fill out without high tin content.
It also does add toughness, not hardness to bullets.

[dtknowles]

Adding 3% tin to a 10 pound pot will cost you less than $8. It would add about 2 cents per 200 grain bullet. If it was me I would cut my 97/3 (50/50) with almost pure to 98.5/1.5 and add 1.5 percent tin. This would be a better alloy than 97/3 for about the same price. That said, I would really need to know more than what is your target. I shoot strait linotype in my benchrest rifle because it seems to be more accurate. I add tin to my range scrap for pistol bullets to improve my production.

Tim

[Rcmaveric]

I just turn up the heat and run the molds hotter for better fill out as or if needed.

But yes adding tin would make it an easy casting alloy. The closer you get to ternary alloy the easier and more butifull it cast. That convience fee comes at a cost.

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[mfraser264]

Tin is believed to reduce the grain size of the Pb-Sn-Sb alloy and it certainly helps helps cast fine small details and sharper corners. Agreed that 2% is about all you will need to add. You can get Food Grade Pewter and the local thrift stores if you are not in a hurry for rather reasonable costs. I'd stay aware for Decorative Pewter. Look for plates, mugs and candle stick holders with Hallmarks. I've always been amazed with Linotype that I can see the cutter marks from the Cherry when the right pouring temp is dialed in.

[bangerjim]

Tin is believed to reduce the grain size of the Pb-Sn-Sb alloy and it certainly helps helps cast fine small details and sharper corners. Agreed that 2% is about all you will need to add. You can get Food Grade Pewter and the local thrift stores if you are not in a hurry for rather reasonable costs. I'd stay aware for Decorative Pewter. Look for plates, mugs and candle stick holders with Hallmarks. I've always been amazed with Linotype that I can see the cutter marks from the Cherry when the right pouring temp is dialed in.

Sn reduces the surface tension of the mix. That is why you "see finer grain" details. And why they use higher % of Sn in the old lino alloys - to get the letter details.

[fredj338]

I cast for rifle and pistol, don't use tin. It is expensive and unless really required - why bother? I do see a use for casting with pure to get decent fillout. Some appear to use it to get expansion, IMHO it is just so the mould fills well when using pure. I did use some when I cast pure + zinc so the fillout was good.

^^THIS^^
I rarely add tin to an alloy for handgun bullets. Is mostly range scrap & maybe a bit of lino, which does have some tin, but as long as the mold is filling out, why waste money?

[ebb]

I have no right to tell anyone to use tin or not i have only cast one batch of bullets, and many of them were ugly. If I can find some tin with out going to Roto metals and paying $18.39 a lb for it I will add 1-2 percent to my next batch and see what happens. I don't see how I can make bullets look any worse than last time, but who knows maybe I can. I talked to my friend about using some of his pewter mugs, but that didn't go over to well.