Nuclear Medicine Lead

[JWFilips]

Hi Guys,
In a trade for some range brass, I got two 8" x 4" x 2" Blocks of, what the guy told me, are from a guy whose Father works in the Nuclear Medicine department of a local hospital. I have no idea what the stuff is but I know I can scratch it with my fingernail somewhat and it has that dark gray appearance of pure lead.
One of the blocks looks layered like it was in a mould and molten lead was added to it a number of times ( about 8 layers are discernible). The other block is a solid pour.
He told me he could probably get me more of these if I could use them.

I looked up the composition of " Large & Small Cores" on the Alloy calculator from CB site it it shows beside mostly lead there is some tin and antimony in those….. but I'm just not sure if it really is that stuff or not.

Any thoughts?
Thanks
Jim

 

[Tony]

The isotope containers came in two alloys that I am familiar with. One is 96/3/1 and the other is 96/2/2. Both are very useful alloys if that is what they are. If they came from shielding material, your alloy is likely closer to pure lead. Hmmmm......

 

[yodogsandman]

Get it, get it all if the price is right! You can always heat treat some to see if it hardens up. That would confirm the antimony content in it. That should be a nice clean lead to alloy with or use as is.

 

[KHornet]

I have in the past had quantities of the lead bricks used for isolation of radioactive materials. Always treated it as soft lead.

 

[Dusty Bannister]

If your measurements are correct, that slab might weigh about 25.3 pounds if pure lead. You may want to compare the hardness with a known alloy by placing a ball bearing between the known and unknown ingot and compress in a vise. At least you will have some indication of "harder than" or "softer than" to work with. It could be that the fellow melted down small containers and poured them into a mold to make storage easier. Nice addition to the stash. Dusty

 

[JWFilips]

I have them stashed in my shed and now that the weather is getting nicer around here I will probably get out my trusty "Pencil Set" and get an idea of where the bhn is

 

[Ian]

The bricks are just portable shields, usually are soft lead which don't adhere to a particular specification like the containers do.

 

[gtgeorge]

If they are painted gray and weigh in around 25lbs with the lid then they are likely pure. I had gotten some awhile back and they were too soft to even measure with a LEE tester. Finding a different chart they were about 5.5 BHN by measuring the indent with a caliper. Softest lead I ever ended up with.

 

[fiver]

if they are beveled on the edges so they lock together they have about 1-1.5% antimony in them.
I got a couple hundred pounds of them a while back and use the alloy to make swaging cores with.

how I'd work with it is to buy it all, all he has.
you then end up with a good but maybe unknown lead alloy [shrug]
throw some lino-type in with it at a ratio of @ 4 to 1 and go ahead and cast with it.
the worst that happens is you end up some 2% tin and 5% antimony alloy.
compare it to the weight of some of your ww or whatever alloy boolits.
if it's lighter add more of the lead if it's heavier use more lino once you get it close in weight, your % of stuff inside the alloy besides the lead will be close too.

but I'm pretty scientific like that.

 

[JWFilips]

OK I got to check them out closer today: Even though at first they appear & Measure similar . One is most definitely a layerd block with different alloys making up the layers.
That layered block also has a slight hollow in the top from cooling no doubt and there is a screw embedded in this area.
The top layer test at about BHN 11- 12 the bottom at about 9-10 While the bottom & sides are sharp right angles the top edges are rounded.
See photos:
The other block while exactly the same size is heavier darker color and looks homogenous all edged are sharp right angles and no signs of a cooling area from a pour: it test at about 5 BHN on all sides See photo below.

 

[fiver]

bet the bottom 2 go tud when you drop them too.
I bought a couple of them bricks [weighed right at 25 lbs airc] and I treated them like straight lead.

that other one looks like they just poured whatever they had kicking around into a pan [mold] of some sort.
it could be from isotope cores as the bhn's sound about right for the 1/3 and 2.5/2.5 alloy's they generally use for them.

 

[quicksylver]

If they glow in the dark I will take them off your hands....my nephew has about 590 #'s of the stuff it works great as is or you can blend it...

Jim I look at it as the "new" wheel weight material....

Gather all you can....Dan

 

[quicksylver]

Jim ...as an aside note..my approach with any unknown alloy is rather unscientific but effective for me...mainly because it is simple...I have records of bullet weights cast with known alloys...

When casting with an unknown alloy if the bullet is heavier than my "norm" I will add some lino ...if lighter i will add lead or COWW...until I reach the target weight...my bullets will vary slightly from BATCH to BATCH but will be consistent within that batch....

I have noticed that Ben uses COWW plus some tin ...I use a 92/4/4 alloy ...I think it's safe to say that both alloys shoot great AND with about the same powder loadings and velccity....

I think it's safe to say that any alloy in between would shoot as well......

Just ...my observation ...it has also eased any "anxs" I have had over alloy.....but then again I don't drive my bullets hard....

My parting shot....I like my alloy around the 14bnh. area... for fill out.....but have found that most anything will work..accuracywise..