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rrob692326
05-04-2015, 03:15 AM
I have a question I am mixing up a batch of alloy( 500lbs). and would like to know what is the minimum percentage of antimony I need to be able to heat treat my boolits properly. I have added the appropriate amount of arsenic via lawrence magnum shot and I have 2 percent of tin set aside, just don't want to waste expensive 30% hard antimony lead. I usually use coww but my supply is running low and coww are nonexistent in Hawaii. I always thought coww were 2% antimony but according to some online articles the percentages are different. I always got good results with coww whatever the antimony percentage is, so if nothing else can you clear that percentage up. Also the LASC articles seem to say you need 4 to 6 percent antimony for optimum results. Will increasing the antimony content retard the age softening process? Thank you for your help in clearing these matters up.
Aloha

Lloyd Smale
05-04-2015, 07:15 AM
you shouldn't need antimony if you already have arsenic in your alloy.

sqlbullet
05-04-2015, 09:47 AM
Depends on how hard and brittle you want you resulting bullets. Personally I am happy with 3%.

GabbyM
05-04-2015, 09:57 AM
2% SB + 1% Sn. As long as you have a little arsenic. Heat treat in oven or water dropped from mold. You'll have a hard enough bullet for most shooting.

You didn't state what your current alloy is or for what application the bullets will be used. The Lawrence shot should have around 4 to 5% Sb.

runfiverun
05-04-2015, 10:29 AM
the lower antimony percentage will respond just fine to heat treating of the alloy.
it just takes the lower amounts longer to get to their final hardness.
3% antimony is plenty enough to see results.
2% will also respond to heat treating just fine, your final bhn will of course be lower.
keeping the tin amount to just enough to cast well with [.5%] is also going to help your heat treating by allowing you to use a higher oven temperature which in turn increases your final bhn.

bangerjim
05-04-2015, 05:18 PM
3% Sb for all my boolits. No more, no less.

rrob692326
05-04-2015, 06:58 PM
Thank you for all the informative replies. I am shooting for a brinell of 18 plenty hard enough for my heavy 357, 44, 444, and 45/70 and midrange 8mm 7.62 x 39. I am glad I don't have to use 6 percent antimony as that would be quite expensive to blend as 6% of 500lbs is 30lbs of antimony thats like 17 bars of superhard 30% at 19.95 per bar or about 340 bucks plus the 4 bags of lawrence magnum shot! I will be adding 1 percent tin. As according to some. 2 percent accelerates age softening does that sound about right or is that still to much?. Sure was easier when I had lots of wheelweights. Great to belong to a forum that helps people and not ridicule or chastise them like some of the other forums . Says a lot about character.
Mahalo Nui Loa
RR

454PB
05-07-2015, 10:44 PM
If 18 BHN is your goal, you could use as little as 2% antimony. I get 24 BHN from COWW alloy water dropped, oven heat treating will increase that.

Defcon-One
05-08-2015, 09:00 AM
Since you have 2% Tin, I'd Match the tin at 2% SB or go to 3%. No more is needed.

But I would just use it that way without the effort and wasted time of heat treating which I do not personally believe does a thing to help!

DC-1

runfiverun
05-08-2015, 11:18 AM
the higher tin amount you have will lower the amount of heat the boolit will take in the over before it starts to melt.
a bhn of 18 should be easily achievable with 1% tin and 2% antimony I would target about 390-f in the oven.
with a 1 hour soak time [in the heat] then dump the whole thing into cold water right from the tray.

remember that what your dial and what the internal temp of the oven actually is will differ, so you should use an internal thermometer to test what you are really getting in there.
use a small batch of reject boolits to find your maximum temperature [before they melt] then back that down.

now get them size/lubed and then give them a month to settle down.
the whole batch will come to the same final bhn but it will take them a little time to get there, and the lower the antimony content the longer it will take.