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Post by rangeball on Aug 3, 2011 14:59:31 GMT -5
Was doing some googling on how to anneal copper dead soft. Most everything says heat read hot and let air dry or water quench. Not much info on time to hold red hot.
Then it hit me. I have a client that makes pottery. He has a kiln that gets 2000*+. I'm sure I could get him to do whatever we need.
So to get a copper bullet dead soft, what temp and for how long? Water or air quench?
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Post by 10ga on Aug 3, 2011 16:09:08 GMT -5
I water quench when annealing rifle and pistola brass after the 1st loading and for major resizing. Makes them last a lot longer. Guess it'd be the same for copper. 10
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Post by rangeball on Aug 3, 2011 16:21:43 GMT -5
Found this-
Can anyone convert that to Fahrenheit?
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Post by DBinNY on Aug 3, 2011 17:25:09 GMT -5
700-800C=1292-1472F
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Post by rossman40 on Aug 3, 2011 19:18:24 GMT -5
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Post by youp50 on Aug 3, 2011 19:18:52 GMT -5
I do not know temperatures, I do know colors.
Color sequence as temperature rises is brown, blue, red. Blue is the color I shoot for when annealing. Air cool or quench offers the same results, I air cool as it is less hassle/mess. Red will get the copper oxidizing and black copper oxide flakes off after it cools. My guess is that red hot would be too hot to anneal after sizing, due to the oxide layer reducing bullet ID. Knock the oxide off and then re-size and you could be in luck.
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Post by rossman40 on Aug 3, 2011 19:30:33 GMT -5
If oxidation is a problem you could use 101 copper alloy which is oxygen free, of course about 30% higher cost.
Perhaps SW can tell us if the bullet diameter changed during his annealing.
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Post by edge on Aug 3, 2011 21:01:31 GMT -5
Long soaking times are generally for homogenizing and that is not what we need. That is more for castings or where you want to promote grain growth. Annealing is done with Copper between 750 and 1200 F The higher temps are for other copper alloys. Back to our needs, SW came very close to the hardness of the Barnes which has been the ideal....as far as I know. When in doubt crush a bullet! A poor mans hardness tester is to take a piece of material with a known hardness ( Barnes bullet ), then take a ball bearing and the bullet you want to test ( must be same diameter as the Barnes ). Put the two bullets in a vise with the ball bearing between them and tighten. When the ball bearing indents it will dent both is proportion to their hardness. If the dent is Larger on your annealed bullet than it is softer than the Barnes. I am sure there is an actual calculation to tell you the hardness but I don't know it...and I am satisfied with the Rockwell testers I use at work There is a ratio for lead but I have not seen that in quite a while. A bullet caster may know the dent ratio between pure lead a WW or some other hardness. edge.
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Post by rangeball on Aug 4, 2011 9:01:24 GMT -5
Interesting stuff guys. I was thinking the kiln would be ideal to get a high temp held exact for the correct amount of time.
I snipped this out of Tom's post in the full form die thread-
Not sure to interpret this as barnes doesn't anneal all their bullets or he's talking about annealing the barnes over and above what they do, which would lead me to believe they could be made softer than the one's we are shooting. My gut says the latter.
Is there a magic temp/process/time frame to get them dead soft as opposed to just softer? I can only imagine softer would be better if at all possible.
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Post by edge on Aug 4, 2011 9:41:48 GMT -5
FROM: Heat treater's guide: practices and procedures for nonferrous alloys By Harry Chandler
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Post by rangeball on Aug 4, 2011 10:45:28 GMT -5
Link to annealing discussion at Swing Lock (scroll down)- www.swinglock.net/page10.phpThe hot plate is interesting. I wouldn't have thought it would get hot enough. What happens if you leave the bullets too long at the correct temp. Do they get softer or does something undesirable occur?
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Post by edge on Aug 4, 2011 10:56:33 GMT -5
I would imagine that with pure copper the grains would grow but it would not matter in a bullet.
A piece of copper as small as a bullet will maintain a uniform temperature within your measuring capabilities. When the outside is 1000 F so is the inside for all practical applications. There is just too little mass to slow heat transfer down.
edge.
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Post by Deleted on Aug 4, 2011 14:52:22 GMT -5
My bullet making friend at HAWK ,Andy and I discuss annealing again, he has a feeling that the way CEB made the bullet might be hampering the annealing efforts. Other bullets are HAMMERED into shape not just cut so there is a different structure composition. I tried to get him to get some bullets from Rangeball and do his annealing process to them for a try. His response is what I mentioned above. And he didn't think it would work. Maybe he has a point,maybe he doesn't Thats what I came up with .
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Post by rangeball on Aug 4, 2011 16:22:08 GMT -5
Does he think their machining is work hardening the copper to the point it won't soften? Does he think they are starting with too hard a copper?
I don't know much about this subject but my gut is having a hard time buying this explanation unless I'm missing something which is entirely possible.
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Post by youp50 on Aug 4, 2011 19:09:58 GMT -5
I am fairly certain that the only copper you cannot anneal is copper that is already annealed. Probably can anneal it, just will not result in an improvement.
If you are going to anneal with an electric furnace of hot plate, you could set up a nitrogen purge. Copper will not oxidize and flake off then.
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Post by Deleted on Aug 4, 2011 19:47:18 GMT -5
From what Andy was telling me the HAMMERING that a press/die does to form a bullet, compresses the copper into another animal compared to a swiss lathe cut bullet. I think were just scratching the surface on metallurgy, and bullet making ,but we are learning which is good. Rangeball, the Kiln might work try it out nothing to lose there,who knows.
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Post by GMB54-120 on Aug 4, 2011 21:03:43 GMT -5
I small arts and crafts kiln should work fine and large enough. We used them in high school for melting a ceramic glaze on pottery and other things. It got plenty hot.
WOW those things got expensive.
NM.
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Post by rossman40 on Aug 4, 2011 23:30:07 GMT -5
Barnes and Remington bullets are swagged/press formed. Remington and Nippert's patents say they anneal after the bullet is formed and from what I read in Barnes patent they anneal after the primary sizing and before the nose is formed which is probly why they look so perfect expanded. The petals remember how they were folded and are harder. Probly the biggest reason to anneal a Barnes would be to get the shank back to dead soft for better sizing/obturation and/or soften the petals up for improved low velocity terminal ballistic performance. Another question would be after annealing a Barnes is how does it effect terminal performance?
As far as cutting on a lathe, I doubt if it would change the temper that much if you had sharp tooling and coolant flowing.
If oxidation is that much of a problem effecting size you could just spec the bullet a few .001s bigger to make up for it. Another interesting fact while the Barnes patent mentions 110 alloy the Remington and Nippert patents list a wide range of alloys but the alloy of choice is 102 which is oxygen free, so much lower oxidation during annealing. A buddy of mine has a small furnace to heat treat parts and to prevent steel from forming scale he wraps the parts in stainless steel foil.
Another thing is how low do you want to go? While you can anneal a Barnes a bit more, even to dead soft do we want to go just lower then the Barnes hardness or full dead soft? Supposedly dead soft 110 copper has a Rockwell hardness of F40 (HRF 40), I do not what that would be in BHN. Would it be low enough for a simple (and cheap) Lee hardness tester to work? You can probly easily get the 110 copper to 90-95% dead soft just by running the temp up to over 1000° for a few minutes. To get that extra 10% you will have to run it up a bit higher to 1200°F+ and play with the time.
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Post by rangeball on Aug 5, 2011 9:36:18 GMT -5
Tom posted this in the other thread and I thought I'd add it to the discussion here for posterity- rangeball, To answer your question, it could be that Barnes does some degree of annealing on there bullets but if so, they are far from being fully annealed. After annealing, it is amazing how much easier the Barnes TSX bullets push through the die. The force difference is very significant making the annealed bullets probably the easiest of all bullets to resize. To anneal bullets, there is no need to get overly technical about the process since most shooters don't have easy access to special equipment which really is not needed any way. To anneal the subject bullets, it can be done with a cheap electric hot plate or red / orange hot stove burner. Before turning the burner on, stand a number of bullets on the burner coil and turn on high. Let the bullets cook for at least 20 minutes. The bullets will turn black before they are done. Then, pick the bullets off with a pair of pliers and drop in cold water. That's all that is required. Certainly not highly technical but in my experience gets the job done very well. During the quench, most of the black oxide will flash from the surface leaving a bullet with a somewhat frosted surface. The frosted surface may actually have an advantage in that it holds sizing lube very well. I blow the hollow point cavities out with air to remove water. Tom The "far from being fully annealed" intrigues me. I would think with proper tip design as soft as you could get it would be best? Comparing to jacketed lead bullets, the ones that seem to shoot the best in the widest range of barrels are the softest, like the parker BE, to a point. I'm thinking strongly about taking the 6 or so CEB V1s I have left and annealing them like Tom mentions. Only problem is I have a gas stove, but I think my brother has an electric in his basement. If he does, nothing left to lose and I could send one to Edge and see how the hardness compares to the last round of testing he did, if he's agreeable. If they are noticeably softer I could try them sabotless in my 99.9% completed .45 (just waiting on the alumahyde II to cure).
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Post by rangeball on Aug 5, 2011 13:22:22 GMT -5
Does this tell us anything new? buau.com.au/english/files/110.pdfconverts to 707-1202F, so right in line with rossman saying the magic number is 1200f, but doesn't address time. I don't think a stove top oven will get that hot. Maybe 700f though, and it would seem you'd need longer time at the lower temp to get the same job done? www.keytometals.com/Article25.htm
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