10 % tin

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  • Last Post 03 September 2009
tturner53 posted this 22 August 2009

I made up a 34 lb batch today. May have got ahead of myself, did the math after. Into the pot went aprox. 30 .lbs ww, 2.5 lbs babbitt(90%tin,7.5% ant. 3.5%copper) and a crunched roll(about 2lbs. ?) of mystery solder. I can't tell you what I was thinking but it made sense at the time. Now I have what I think is about a 10% tin content and about a 3% ant. content lead alloy. Turns out that high tin content will make heat treating go poorly. I have lots more of everything, any suggestions? I'm looking to make some real hard bullets. Any guesses what the bhn would be on that mix? Call me impulsive.

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hunterspistol posted this 22 August 2009

     I think you've got something about 15bhn without heat treating. If you're looking for really hard, try wheelweight and linotype heat treated. Of course I think straight wheelweight heat treats well enough without alloying it at all.  I've never gotten an alloy to stay all that consistent but, I've water quenched some before and, golly, they were hard!

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runfiverun posted this 23 August 2009

mix 1 lb of that to bout 12 lbs of ww's and waterdrop them. your bhn will be round 18 after 3 weeks. you can then heat treat them to round 30 or so.

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tturner53 posted this 23 August 2009

Thanks guys. I'll do the 12/1 ww thingy. 30 bhn makes me drool a little. I have a couple pointy molds for .30 and .22 I want to launch. I was so proud of all the tin I scored I got carried away!

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tturner53 posted this 23 August 2009

Now I have a pretty good idea of the downsides to too much tin, I'm making up some new alloy diluted with ww. If we disregarded the waste of money and negative effects on heat treating, is there any good side to high tin content?

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hunterspistol posted this 23 August 2009

      :coffee  Castibility, the bases fill out better. That's what the tin if for! Supposedly makes the bullets more consistent. I don't have any tin and, from time to time, it would come in handy.

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runfiverun posted this 23 August 2009

tin also loves antimony and makes it a stronger chain. just don't use more tin then antimony it can cause hard/soft spots in your boolits. low amounts of tin/antimony in an alloy will harden a boolit enough but leave a tough malleable alloy. whereas a higher antimonial content will harden a boolit but add brittleness to it. the best compromise to the tin antimonial mix seems to be right at 2/4 after that the brittleness of the alloy takes over and you lose toughness. i try to get close to a 1 tin/3 antimony mix this works well up into heavy magnum velocities in revolvers and leverguns without a gas check. and water drop it for general rifle work up to about 2200 fps,with a g/c.and can be the way to go for some pistol calibers of higher pressure like the 40 and 9mm. it also will heat treat pretty well.

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tturner53 posted this 23 August 2009

OK, now I have the alloy made up, about 24 lbs. of ww + tin(maybe 3-4%?). This should be versatile stuff, based on what I'm reading. As is should be good for GP stuff, water drop for more hardness and heat treat to get the hardest bullet possible. (None of this will be used for hunting where expansion will be an issue) If I'm getting it right, water quench before heat treat to get maximum hardness? Maybe I'll take another shot at the 9mm, last effort wasn't good. First I gotta run over to a job, I stained a concrete floor in a lady's house and she doesn't think it looks “rustic” enough. I think my grinder will fix that. Hate to work on Sunday but it's gotts be done.

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hunterspistol posted this 23 August 2009

      :coffee It's my understanding(I might be wrong) that if you water quench, you shouldn't heat-treat in an oven following that, or vice versa.  Everytime you heat the bullet, you're losing the temper or whatever hardness you've gained.  To heat-treat in an oven, air cool, then heat treat in the oven. Both techniques require a cool water quench-it's this sudden realignment of the crystalline structure that causes it to harden. To heat it again would be to lose the realignment in the crystal formation, or lose the temper and soften the bullet. 

 The difference, I believe, is the amount of time the lead is hot.  With water quench it's liquid when poured and immediately quenched.  In the oven, it's a solid, heated to this point, then quenched. The bullet would be hot for 45 min. to one hour so, it leaves more time for the structure to realign while still in the form it will be, rather than converting from liquid to solid and quenched immediately.  It gives the structure more time in it's desired form to accomplish the hardening.

     I should stop reading someday but, that ain't gonna happen!

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tturner53 posted this 23 August 2009

Making progress on this experiment. Now I know, you either quench OR heat treat, no advantage to doing both. Probably still a little high on the tin, but I'm going to shoot some to see. They won't last long enough to soften up much. I cast a hundred #315s, about 50 Ideal 224450s and 50 Ideal 311413s, all water quenched. The old Ideals are both spire point designs that were dropped a long time ago. Loads to be for Hornet and mainly '06, but have a lot of other 30s to mess with.Oh, also .223 Rem. I read somewhere that you need to handle 1500 fps before you go for 2,000 and up. I'm just going for it!:taz: Edit; also cast up about fifty Ideal 308334, also a obsolete spire point. I know spire points aren't usually great for cast bullets, just something I want to try. It'd be cool to get near jacketed velocity and accuracy from a cast spire point.

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tturner53 posted this 24 August 2009

Did a okie hardness test on my new alloy. Crossed up in a vise with a commercial linotype bullet my bullet won. The linotype caved in and my bullet didn't have a mark! I like this! But we still have to see if I can make 'em shoot. Thanks to all of you who helped me along, I know I can be a little slow sometimes.

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runfiverun posted this 25 August 2009

let the water quenched sit for 3 weeks to obtain full hardness. if you use a nose punch to size you can bend a new boolit or flatten the nose. be careful,i like to size w dropped asap but not too much or too soon. i even go so far with my stars to do one boolit at a tim i check and size then use a small boolit sized rod to push it out and do another one.

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madsenshooter posted this 03 September 2009

From bits and pieces I've been reading, one of the fellows who first started working with cast bullets, the designer of the .311284 for the Krag was using high tin alloys.

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runfiverun posted this 03 September 2009

high tin alloys with no antimony. like rcbs and lee uses for their rifle molds. 10% tin 90 lead.

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RicinYakima posted this 03 September 2009

According to the Ideal Handbook #16, 1904, prior to the invention of gas checks, the target shooters, Dr. Hudson and Mr. Kephart, were using 80% lead, 10% tin and 10% antimony. Hudson finally settled on 86/7/7 for the best alloy for this time period. A standard load was 8.0 grains of Unique. HTH, Ric

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tturner53 posted this 03 September 2009

Thanks Rick. I'm on a pretty steep learning curve regarding alloys. Roto Metals gives a formula for calculating bhn on their website, but it is confusing to me. According to their formula the alloy of 80/10/10 would be about 21 bhn, which is lower than Linotype, but has a higher tin and antimony content than Linotype does. Something doesn't add up. At any rate, it appears to me that the only hope of hitting a 40 on the Brinnel scale will be by heat treating some mixture very carefully. It has also been brought to my attention that commonly available hardness testers will not even reliably register a 40 if I got it. This is all pretty academic for a guy like me, so I'll probably just run over to Roto Metals and get 5 lbs. of their 'super hard' alloy(30% antimony/70% lead), mix it with some wheelweights to cut it back a little and add some #1 babbit, then oven heat treat that. They should be pretty darn hard and hopefully a little fatter, then I can see if my #308413 , #224450, or 308334 will hold up to a full house load. Naturally I'll work my way up slowly to avoid surprises. Disclaimer: I never said this was either smart or useful or even likely to be , just something I want to try.:D   EDIT: If you're interested see “ball ammo equivalent” project thread.

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