No arsenic?

[leftiye]

I just got a new saeco hardness tester today, and the first thing I used it for was to test some .357 200 gr. rnfpgc's that I just finished casting. Before and after heat treating that is. Before they were a Saeco six number ( Brinell 9) and afterwards they were a S-7 (bHN 11).

This is a problem. The alloy was 1 part lino to 2parts pure with a little tin added. Previous info said that would be about a BHN 10 as cast, and a BHN18 approx after heat treating. The only guess I have is that there might not be any arsenic in the alloy.

I'd add a little arsenic, but I don't have any. I've heard that there is arsenic in wws, and in Magnum shot (50 lbs went for $72.00 on fleabay tonight). There's also possibly some in chilled shot, does anybody know? I've heard that it is not in linotype (I guess because it is always used in printing as air cooled)? Are these ideas correct?

Any body got any other ideas as to why this stuff won't harden? I tried it first at 475 degrees, then again at 500 degrees, same result. Or does anybody know any other sources of arsenic?

[OLPDon]

You didn't state how long of a time period after heat treating it can at times take as much as a week to come to hard BHN. which is a good thing when and if you need to size the Casts after it reaches it hard state and give your lube sizer a workout. If you haven't waited to test BHN wait a week and see were it goes.
It was stated on past post water with a little dish soap just dip in solution to size Cast with out using your regular lube. Sound like a winner to me I will give the water with dish soap a try.
Don

[leftiye]

No, I didn't wait any. I'd heard that a week or two would allow them to normalize, but it plumb slipped my mind. Be a lot cheeper than that $80 (including shipping) for magnum shot too! Guess I've never had a hardness tester before, so I never tested after allowing time to normalize.

One should size before heat treating, the sized lead will revert to soft lead, and you don't want that. Problem is, I want to size them larger, and I ordered dies from Lyman, but they won't be here for at least a week. Thanks, Ted

[waksupi]

Good advice so far. Most alloys will test at nearly pure lead, when fresh cast. I'd give it at least three weeks to see the average hardness after casting, and before heat treating, if you just want to see the variation.

[BerdanIII]

There is arsenic in birdshot; it's there to increase surface tension of the molten lead and make the pellets more uniform before they hit the water at the bottom of the shot tower (or in my ex-company's case, shot well). We used to get our arsenic from Mexico.

[BABore]

You can safely size immediately after HT without affecting the future (2 week) hardness. Since you have to wait for your new sizer, I would do this. Leave a couple out for testing. Put the rest in your freezer. This should retard the hardening process. I've only done it for a couple days and it worked out. When you get the sizer, let the bullets come to room temp. and test them. Also test the couple you left out to see where they're at.

Worst cast; your bullets are already hard when your sizer arrives. Put them in the oven at 300-325 F for an hour, then turn the heat off. When cool, they will be fully annealed. Reheat treat them and size. PITA but it'll work.

For future reference cast a few bullets up, air cooling some, and WD some. Hardness test both samples immediately. I can tell the difference with 50/50 WW-Pb alloy. Test them again in a week or so. After a little history you'll be able to tell if the WD samples have the ability to harden right away. I can feel the difference when running them through a sizer an hour after casting.

[leftiye]

BaBore, Thanks for the ideas. Thank you all. Like I said above, it just slipped out of my mind. I checked one today and it was BHN 22! As Ba said you can solve most any problem between HTing and annealing (and alloy adjustments). Now to see if I can anneal only the noses! Ted

[3sixbits]

I'm highly suspicious of any alloy that contains any excess of 2% Sn, for heat treating! The true analytical composition of all Linotype metals contains from the low end of 0.06 to 0.10 As (arsenic). I know of no one that claims you can heat treat Linotype bullets that contain from the low end 2.50 to as high as 8.00 Sn. Yet all the Linotype alloys age harden and can take as long as three weeks to reach full hardness. Temperature and humidity are factors in this time factor for age hardening and I believe this is why the three weeks are given as the time (maximum) given. You will note that people have reported that age hardened bullets after they have age hardened, they remain hard for years. This is not the case with oven tempered bullets that do a reversal after two years and age soften. Just my two cents!

[leftiye]

Hopefully my boolits will long be done shot before two years. Though I do have some that have sat around that long. I guess I'll just heat treat them before loading in that case.

Ironically, up to ten percent tin will alloy in a true lead/tin alloy. My purpose is more to try to make a boolit that will expand reasonably well, and shoot well at good velocities. (though the overall picture is that you can't out do the J-word bullets for either expansion or velocity) With this in mind, I guess the answer may be that the tin is more important for holding a soft boolit together than the velocity might be. (though I'd expect a 10% tin boolit to still shoot pretty fast as it would be fairly hard too. E. Keith liked 5% tin 95%lead at BHN12 for magnum 1200 fps 44 loads). As far as tin's effect on how hard a metal can be heat treated, I guess I'll just have to find out the hard way (no pun).

[Ricochet]

You will note that people have reported that age hardened bullets after they have age hardened, they remain hard for years. This is not the case with oven tempered bullets that do a reversal after two years and age soften. Just my two cents!
Unquenched boolits will never harden by aging alone to the hardness of heat treated, quenched ones. Quenched ones will never soften to a lower hardness than aged, unquenched ones. They're going to the same equilibrium point over time.

[leftiye]

I believe that unless quenched, they won't harden appreciably. I could learn something - if I'm wrong, Let me know. (it does violate the concepts of hardening as displayed in other metals)

[BAGTIC]

My HTWW bullets have always tested hard (BHB 20-28) soon after casting. Bullets heat treated to very hard BHN will slowly soften over a year or so but usually stabilize at about BHN 20-22.

[3sixbits]

Unquenched boolits will never harden by aging alone to the hardness of heat treated, quenched ones. Quenched ones will never soften to a lower hardness than aged, unquenched ones. They're going to the same equilibrium point over time.

Memory is a funny thing, when I read your post It triggered a memory of something I read when I was a first year student in metallurgy. Lucky, because the book store was a rip off (giving pennies on the dollar) for buy back, I kept all my old text books. There is a difference between quenched and oven treated and quenched lead alloys. Now if you want to discuss quenched and age hardened, you have to consider them in a separate category from quenched and just age hardened. Heat treated and quenched will definitely soften over time and will not age harden. Quenched and age hardened will not soften over time, it would be slick if I could reproduce the graph for you. I've got to thank my wife for finding this book in the stacks, when I asked her if she remembered seeing it, I watched her walk to one of the many book cases in this house and lay hands on it. If it had been up to me to find this book, I would still be looking for it.