I've read a bit about how adding copper to the mix increases the toughness of of the alloy. most threads get very confused about how to do this because people start talking about several methods at the same time. So to help that please state a method used if you want to comment about a process so we can keep track of which we are talking about. Thanks, Rodney
How can you get copper into your alloy?
- Thread starter 3856imp
- Start date
RBHarter
West Central AR
I derive my "1-20" from tamper seals like those found on gas meters for example . During the clean up melt it is believed that the tin content leachs to saturation copper from the copper wire the seal is held with .
I also sort the range metal and find that the large cal pistol and plated bullets tend to make tin stringy alloy which I believe is dissolving copper from the plated bullets into solution .
Copper is really the best explanation for why I get what I get from some of the rifle bullets I shoot . At best I'm getting 0.5% probably closer to 0.45% net in the seals maybe more in the stringy alloy .
My finished to pour for rifles cut 75% with WW is about 18 bhn but shoot like 22-24 on target but when they arrive they tend to act more like 14 .
I also sort the range metal and find that the large cal pistol and plated bullets tend to make tin stringy alloy which I believe is dissolving copper from the plated bullets into solution .
Copper is really the best explanation for why I get what I get from some of the rifle bullets I shoot . At best I'm getting 0.5% probably closer to 0.45% net in the seals maybe more in the stringy alloy .
My finished to pour for rifles cut 75% with WW is about 18 bhn but shoot like 22-24 on target but when they arrive they tend to act more like 14 .
358156 hp
At large, whereabouts unknown.
Check out their babbitt alloy page, they lay it out nicely there.
fiver
Well-Known Member
buying it is by far the easiest way to get and keep it in solution.
back when I first started messing with it I used a high tin solution and weighed the copper out using fine strands of short cut off speaker wire.
later when we revisited the idea Popper brought up a method of exchanging copper in for zinc using copper sulphate.
some tin will also be pulled out of the alloy and I like to add a little zinc to most of my alloys [along with or instead of the copper]
so I tend to prefer weighing out my tin and copper in a 3-1 solution then adding what I need for the copper percentage of about 0.3%
back when I first started messing with it I used a high tin solution and weighed the copper out using fine strands of short cut off speaker wire.
later when we revisited the idea Popper brought up a method of exchanging copper in for zinc using copper sulphate.
some tin will also be pulled out of the alloy and I like to add a little zinc to most of my alloys [along with or instead of the copper]
so I tend to prefer weighing out my tin and copper in a 3-1 solution then adding what I need for the copper percentage of about 0.3%
M3845708Bama
Active Member
First copper is a grain refiner, it doesn't seem to make the bullet any harder but it does make it stronger and if you do a hammer test ie. partially beat bullet back to a flat sheet and then break it in a vise the grain pattern across the break is very fine with copper. As to adding copper- copper does not like to combine with lead directly it will go into a solution of sn and pb or zn and pb. It actually goes into solution by replacing the sn or zn with copper. It is a lot easyier to go to Rotometals and get some copper babbit. The next best I have used is copper sulfate. Found at local Co-OP. It is normally used for algea control in ponds. It comes it blue crystals. Do NOT try stirring in crystals when they are blue. they must be heated to drive out the water. The fumes while driving off the water contains some sulfuric acid and can hurt lungs. Not a good method for novice. Best to buy babbit from Rotometals to get it in a specific amount of copper and a lot less dangerous.
M3845708Bama
Active Member
Just trying to learn and keep a promise to the guy who got me started handloading who said " I will teach you everything I know with one requirement--Pass it on"
F
freebullet
Guest
I use a slotted spoon to get those copper jackets out of my melt. The lead comes trapped in them for some reason when I pickem off the range.
Kevin Stenberg
Well-Known Member
I use pewter to add copper as well as tin.
Pewter has so much tin it doesn't add much Cu. I'm on my 2nd bottle of Zep root killer (CuSO4) after 4 yrs of adding the stuff. I use isocore (1% Sn) or add known amount of Zn to Roto high Sb alloy. Add the Zep and stir it in. It will replace ALL the Sn/Zn in the alloy. Wear a paper mask and glasses - remove all the fluffy powder that comes out on top - it is BAD for you - don't inhale it!! Keep your Sb % above the Cu %. Cu makes the alloy hard and maleable. H.T.d 2% will dent a bar of Roto superhard and it shoots fine - just no need for it. I usually run 1/2% Cu for rifle, little less for pistol. Recovered 40Sw 180gr from rock pile - retained 98% wt. 308W @ 50 carved a 6" furrow into same rock pile, none recovered. 165gr 40sw goes end to end through a 150# pig. Cu binds with the Sb preventing long tenicles of Sb which are brittle.
pokute
Active Member
When you add copper to lead alloys, the copper winds up along the grain boundaries. With a lubricating alloy like Babbitt, where a newly worn surface is constantly exposed, this is a benefit. In bullets, there is a potential danger from intergranular copper becoming oxidised and making the bullets brittle. Lubing the outside of the bullet with a neutral pH lubricant should prevent that. If the bullets start turning green, they are losing copper and becoming brittle.
In bullets, there is a potential danger from intergranular copper becoming oxidised and making the bullets brittle.
Sorry, I call bunk on that. Even several yr old 2% Cu are still pristine looking, no green and NOT brittle. I do have some jackeed that have turned brown (oxidized).
Sorry, I call bunk on that. Even several yr old 2% Cu are still pristine looking, no green and NOT brittle. I do have some jackeed that have turned brown (oxidized).
Chris
Well-Known Member
Years ago I got 1000# of #11 babbitt which is, I believe, about 5% copper. The stuff is maybe 85% tin so I use it instead of pure tin in my alloy which is lately based on chilled shot and monotype.
I'm adding way less than 1% copper this way, but I think the it adds some toughness. hard to say for sure, but to me it is a different alloy using the babbitt. It seems less brittle than without, both in 92-4-4 and 94-4-2.
How much copper do you think it takes to modify the grain enough to affect performance?
I'm adding way less than 1% copper this way, but I think the it adds some toughness. hard to say for sure, but to me it is a different alloy using the babbitt. It seems less brittle than without, both in 92-4-4 and 94-4-2.
How much copper do you think it takes to modify the grain enough to affect performance?
fiver
Well-Known Member
you usually have a grain refiner in our alloys already.
ww's and well the older magnum shot has it for sure, some of the newer stuff isn't dropped anymore and has a much lower antimony content than most realize.
it's arsenic, it not only works as a grain refiner it also is a surface tensioner and the small amounts of tin added into ww's are to combat that tendency.
I really think .25-.30% copper is more than sufficient to get the job done as an alloy modifier, up to .5% is going to add some hardness and modify the flow of the alloy under stress.
after that amount it doesn't help as much [incrementally like adding octane booster] and starts to cause shear in the alloy when it hits the oxygen when casting.
ww's and well the older magnum shot has it for sure, some of the newer stuff isn't dropped anymore and has a much lower antimony content than most realize.
it's arsenic, it not only works as a grain refiner it also is a surface tensioner and the small amounts of tin added into ww's are to combat that tendency.
I really think .25-.30% copper is more than sufficient to get the job done as an alloy modifier, up to .5% is going to add some hardness and modify the flow of the alloy under stress.
after that amount it doesn't help as much [incrementally like adding octane booster] and starts to cause shear in the alloy when it hits the oxygen when casting.
M3845708Bama
Active Member
I have not done all the math but I use 6 tablespoons of 26.9% (as matalic crystals copper) in a 20 lb Pro Melt pot and have not reached a velocity where bullets come apart to date. Prior to adding copper I had a lot of bullets coming apart to a gray white dust at about 15 ft from muzzel. NOT a good thing!!! Since adding copper this has not occured and I still get almost full length rifling engagement when fired with no indication of slip. The added copper does not apear to have increased the hard ness but has increased the strength, Like popper, I have bullets over 2 years old and have not seen any indications of the copper breaking down or adverse affects on bullets.