Alloy comparing to 50/50?

[Canuck Bob]

I have been lurking for awhile.

However I just read some serious 50/50 alloy threads. I'm convinced that 50/50 is where I should start on my cast 32-20 bullets. I'm thinking plinking loads of no more than 1200 fps. I'm educated on bullet fit to throat and planning med to slower powder for my long barrel rifle. I hope this is soft launch.

I purchased #9 Lawrence Magnum shot for my base alloy and was planning to alloy 95-3-2 until I saw tin prices. My initial casting doesn't allow a lot of scrounge time so I went off the shelf to start. I would like to play with water drop and HT for the education. The shot has lots of AS of course and I'm told it is app. 6% antimony as it is Mag shot.

What formula would you recommend for me. It seems when guys say WW it can vary due to age and location of the WWs for antimony. I can use one of the calculators to alloy up my blend.

Would 97.5% lead 2% antimony and .5% tin make a workable alloy?

Would less tin still give me good fillout with 2% antimony, I'll be using lead-free solder 95-5?

[btroj]

Give it a try and see. Might cast fine, might need a bit more tin. Every mould has preferences too.
You can get tin based rabbit from Rotometals, a sight sponsor. Ain't cheap but a little goes a long, long way.

[bumpo628]

I'm convinced that 50/50 is where I should start on my cast 32-20 bullets.
Would 97.5% lead 2% antimony and .5% tin make a workable alloy?


I think the 0.5% Tin, 2% Antimony will be fine. It will be very close to Clip on WW. 50/50 plus a little solder has slightly lower antimony.

I have seen magnum shot quoted anywhere from 4 to 6%. LASC says 4%, so that is what I use in my calculations. You can download a copy of my alloy calculator if you want to run some numbers yourself here: http://castboolits.gunloads.com/showthread.php?t=105952

Your ingredients:
Magnum Shot (4 to 6% Antimony, 1.25% Arsenic, Hardness @ 13)
Lead-Free Solder 95/5 (95% Tin & 5% Antimony OR 5% Copper OR 5% ?, Hardness @ 15)
Clip on WW (0.5% Tin, 3% Antimony, 0.25% Arsenic, Hardness @ 12)

If you mix:
10 lbs of magnum shot
1 oz of 95/5 solder
= mixed alloy with 0.59% Tin, @ 4 or 6% Antimony, 1.25% Arsenic, Hardness @ 13

That should be a pretty versatile alloy. It will be harder than WW when air-cooled or water dropped. If you can get your hands on some pure lead you can soften it up a bit. My hardness estimates do not take the Arsenic into consideration, so your actual numbers will be higher.

If you mix:
10 lbs of magnum shot
10 lbs of pure lead
2 oz of 95/5 solder
= mixed alloy with 0.59% Tin, @ 2 or 3% Antimony, 0.62% Arsenic, Hardness @ 11

For reference, 50/50 WW/Pure:
10 lbs Clip on WW
10 lbs Pure Lead
1 oz 95/5 Solder
= mixed alloy with 0.55% Tin, 1.50% Antimony, 0.12% Arsenic, Hardness @ 10

[Canuck Bob]

The shot antimony alloy is supposed to be higher in small sizes. Mine is #9. Lawerence did not respond to my email with an answer.

I appreciate the calculator link, good work.