60/40 Solder

[boatbuilder]

I just got back into reloading after 47 years and the only thing close to lead I have at this time is 60/40 solder that I have about 20 lbs of. I got my molds in the mail today and after cleaning/smoking and lubing hinge pins etc I cast a few bullets. The mold is for a 45-70 Govt. 340 grain .457 Dia. My bullets dropped at .460 which I like however the weight is down to 270 grains. I know that the 60/40 weighs less that range or WW lead and I will melt down some range lead as soon as I can get outdoors and sift through the dirt. But My question is this, does the diameter decrease with a softer lead when casting? I am going to be using the cast bullets in a Marlin 45-70 G with a microgroove barrel and would like to keep the diameter close to the .459-.460 without lapping the mold. From what I can find the hardness on the 60/40 is about 17 BHN.
Thanks

[wmitty]

Those 340 grain Lee boolits are gonna be too small when you cast them with wheelweights or something similiar; at least that's what I ran into with my Marlin. You are right in thinking you are gonna need a .460" boolit for that Marlin. I wound up buying the 350 grain Ranch Dog group buy mould several years ago, and didn't try any further to work with the Lee. I think the Lee might work as a paper patch slug, but have not tried it. Welcome to the club!

That kinda tin content is sorta expensive, ain't it?

[lwknight]

A lot of tin will not cast larger than a little tin. It will be a little harder for a couple years till it age softens unless you just go totally hog-tin wild. You need at least 5% antimony to see a larger cast ( assuming that you have and had good fillout all along ) Even at that it will only add about 1/1000 to the diameter but will add a lot in the way of hardness.

[mikeym1a]

According to the Lyman Cast Bullet Handbook, #3, 50/50 solder is normally added to cleaned wheel weight alloy in the ratio of 9/1. That is, 9 parts WW - 1 part solder. According to that Manual, this is the equivalent of the ' #2 ' alloy, which Lyman recommends for shooting. You could just as easily use 60/40, it would give you a bit more tin. According to what I have read, pure lead shrinks as it cools, while antimony alloys are larger from the same mold. If your Lee mold casts .360 boolits with your 60/40, it should still be that with the '#2'. You can easily get WW alloy from some of the guys here on the site, or off evilbay. Your 20lbs of solder would go along way! mikey :-D

[boatbuilder]

I appreciate the feedback on the 60/40. I do have several pounds of range lead that I got from a private range but it has to be sifted and cleaned before I can melt it down. I will make up the 9/1 mixture as mikey mentioned and check for size, weight and hardness. I bought that solder at a machine shop that went out of business several years ago, it was in a lot with some welding supplies and I got it for cheap. Off course several years everything was cheaper. I have a 50 round box of 22's from a local store that has a .79 price tag on it.
Thanks Guys

[Foto Joe]

If you've got 20lbs of 60/40 that equates to 12lbs of tin at roughly $20 per pound retail!!! I or someone else would happily swap you 20lbs of lead for that solder believe me. Or better yet get on eBay or the sponsor/vendor section here and pick up some reasonable COWW lead and save the solder for yourself to use when adding 2% tin to your lead for better fillout.

The bottom line is you're casting with some extremely expensive stuff there.

[boatbuilder]

UPDATE on 60/40 Solder
I found some WW laying around and melted them down and fluxed it and recast using straight WW. Diameter checked on 4 different parts reads slightly out of round. Bullets measure with Micrometers .4585-.4595. The interesting thing is that using the 60/40 the bullets weighted 270 grains and with the WW the bullets came in at 343 grains. I would not have thought there would be that much difference in a bullet that size. That's like 22% more so if I were to use bullets using strictly 60/40 (which I am not going to do) I would have to use more powder than what is recommended for a 340 grain bullet to get equal velocity's I am to believe.

[lwknight]

The specific gravity of tin is 7.3 and lead is 11.3
The solder is 60% tin so yea, that is totally reasonable to be that much lighter.

[Foto Joe]

What I would suggest is to use that solder and calculate adding 2% tin to your alloy and cast a few again. I think that you will find that your weight will drop by a few grains and best of all your out of round may be cured as well. Wheel weights use a very small amount of tin (it's expensive), so by adding that 2% I think that you will be pleasantly surprised. I know I was the first time I did it.