Casting lead vs tin bullet
Hi guys
Im very new to bullet casting. I tried to search for the right direct answer but seems like the more i search the more mixed answers ive been getting.
Anyway, what is the reason they mixed these two together? I know tin much more expensive and 1/3 lighter. One of the source says, different ratio will give different accuracy at given fps n twist. Is this correct?
Ive tried casting some pure tin bullets. After shooting hundreds of them in my afc barrel, i do notice they are easier to load. Does this means they damage our barrel? Any difference between airgun barrel n pb barrel in terms of material?
Cheers
Ed
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Viewing 12 replies - 1 through 12 (of 12 total)
sorry for late reply josh. taking missus n kido out of town
anyway im shooting 75.6grain .251sized bullet at 920-940fps.
my problem could also be from casting technique. im very new to casting so much to learn. i had a batch that doing 3 inch group at 150m so its a fair start to me.
PB – thats a very useful reading for me. thank you very very very much mate
ed
I have never used Tin, Never!
Always used antimony 5-13% for hard cast bullets for my .454 Casull and .44 Magnum.
I wouldn’t use more then 2% antimony for pellets, especially in the softer steel air rifle barrels. If the barrels are centrefire I would go to 5%.
And how fast are the bullets coming out of your gun? And tin is even more soft as lead, it depends on the content off other mettals in the alloy which you have, but pure tin is bhn 3-4 which is swiss cheese as well. Try pure lead or a 25:1 mix lead tin. Should work gret in your airrifle. And dont size them down to much lets say your mold thows them at .261 and you size them to 251 it wont work because off the uneven dispersion off the driving bands which compromises the concentricity of your bullet to the driving bands. That can as well be a reason for spiraling because the center of gravity shifts out off the center off the bullet.
thank you so much for your input. it does give me some kind of idea. i think somehow the bullet went spiraling. i size it down to .251 and shooting it out of standard factory barrel.
at 33m
at 41m
i shoot many many groups at these distance and all with consistent result. upon inspection, the bullet head seems pretty neat. so could it be from the size? i shoot them tethered to a tank so pressure is pretty consistent. i think im gonna try different sizer etc. thank you so much for the input
ed
Spiraling is typicaly for light short bullets which are fired to hot, try cranking down your power wheel. How heavy are the bullets you are shooti g? A nd how long are they? What size is your barrel? And what size are the bullets. Maybe I can help you sorting out your accuracy problem.
Greets from Switzerland
thank you so much for your input. it does give me some kind of idea. i think somehow the bullet went spiraling. i size it down to .251 and shooting it out of standard factory barrel.
at 33m
at 41m
i shoot many many groups at these distance and all with consistent result. upon inspection, the bullet head seems pretty neat. so could it be from the size? i shoot them tethered to a tank so pressure is pretty consistent. i think im gonna try different sizer etc. thank you so much for the input
ed
Spiraling is typicaly for light short bullets which are fired to hot, try cranking down your power wheel. How heavy are the bullets you are shooti g? A nd how long are they? What size is your barrel? And what size are the bullets. Maybe I can help you sorting out your accuracy problem.
Greets from Switzerland
Hi Josh82
thank you so much for your input. it does give me some kind of idea. i think somehow the bullet went spiraling. i size it down to .251 and shooting it out of standard factory barrel.
at 33m
at 41m
i shoot many many groups at these distance and all with consistent result. upon inspection, the bullet head seems pretty neat. so could it be from the size? i shoot them tethered to a tank so pressure is pretty consistent. i think im gonna try different sizer etc. thank you so much for the input
ed
As i understand that adding a bit of tin would make it more fluid to fill better in the mold, just what would it do if we use all tin? Tin they are harder than lead, to the point where it would damage our barrel i dont know. Some manufacturer may add more tin to prevent damaged skirt n less fouling.
o
Well as an old caster for handguns and rifels I can give me 20 cent. The reason most bullet casters mix like 2-5% tin to their melting pod to reduce the surface tension of the molten alloy as you said to fill out the mold better. The main reason that your bullets are easyer to load is, tin has more shrinkage as it cools down, so your bullets are actualy smaller in diameter, like when you cast them from pure lead. Pure lead has a hardness of arround 7-9 BHN and what we use for handgunbullets is about 12-18 bhn, depends on the caliber, if the bullet is to hard for tha caliber, lets say a .45 acp bullet can be verry inacurate with a BHN of 22, but in a 357 magnum that is maybe exactly the sweet spot. It all depends on the cartridpe pressure, which is arround 60000 psi for a 357, but in a arigun you have way les, so the sweet spot for accuracy may be way down in the hardness range. But propper fit to the barrel is critical to accuracy, for ariguns when you have a barrel which measures .258 you should cast a bullet with .2575 to .258.
Hope that helped you a bit.
The main reason i asked was because it felt like it is much easier to load now with the same size bullet so i thought the lead of the barrel might get slightly bigger. Would that damage the rest of the barrel? I dont know.
As i understand that adding a bit of tin would make it more fluid to fill better in the mold, just what would it do if we use all tin? Tin they are harder than lead, to the point where it would damage our barrel i dont know. Some manufacturer may add more tin to prevent damaged skirt n less fouling.
The use of tin with lead makes for a more consistent metal product . Not too soft and not too hard , just the right metal blend to make
the product a more stable metal projectile .
FROM : THE BIRDMAN
hadn’t heard of pure tin bullets. I’ve heard to use a small percentage to help wet the lead so it will fill the mold better.
They say airgun barrels are not designed for the high speed of powder burners whereas they add antimony to the lead to make it harder and minimize barrel leading from the higher speed.
It shouldn’t be to long before one of our experts fills us in.
Viewing 12 replies - 1 through 12 (of 12 total)
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anyway im shooting 75.6grain .251sized bullet at 920-940fps.
my problem could also be from casting technique. im very new to casting so much to learn. i had a batch that doing 3 inch group at 150m so its a fair start to me.
PB – thats a very useful reading for me. thank you very very very much mate
ed
Good morning ed,
As soon as you find out the casting temperature and casting rhytm which your mold amd alloy likes it is a straight forward process.
The second important step is sorting your bullets, if you are looking for extreme accuracy be ruthles when sorting.
But the best groups which i got at 100 yards with a .308 rifle was around an inch. And the smaller the bullets the more is a little flaw a problem to accuracy. Maybe do a search on the internet there are 3 pdfs from a guy caled beagle on cast boolits amd he wrote a extremly usfull paper which helped me very much when i started casting. Search for: Cast in the 223. If you dont find it pm me your e mail and ill send them to you.
Greets josh