Too much aantimony?

[Magana559]

I worked up a alloy of 75% range scrap and 25% with one pound pewter added for tin. My problem is it casts terrible even when hot.

Range scrap casts OK and wheel weights cast great so I thought together with pewter it would cast even better......well not so much.

Also it's quite soft when I scratch it with my finger nail.

Here are some pics.

The sprue is when I tried to cast like normal from a bottom pour pot and the bullet was pressure cast by holding the mold to the spout.

Need some help and input, I thank you all ahead of time.

[Magana559]

In the first picture you can see where i scratched the bullet with my nail.

[btroj]

75 percent range scrap and 25 percent what? And how much total did you add a pound of pewter to?

For handgun bullets I would stick with plain range scrap. If it is casting well then why change anything?

[Magana559]

Typed this out in a hurry and I haven't had much sleep.

I made a hundred pound batch 75 lbs range scrap 25 lbs of clip on wheel weights and added one pound of pewter to the mix.

I don't know why i messed with it....well maybe it was to find a better blend for pistol. My range scrap didn't do so well by its self so, I thought if I would add a bit of tin and a bit of antimony maybe the blend would do better over all.

Now the batch stinks and I don't know if I should add tin or what.

[btroj]

Ok, the sprue in the first photo is grainy and fractured. That happens easily with higher Sb alloys. Wait a touch longer before cutting the sprue.

Give the bullets a day or two to age and the hardness will increase.

Now is the time to learn about maintaining a consistent mould temp. Highly frosted bullets, and those with rounded edges and lost micro bands, are often a sign that the mould was too hot. Mould temp is maintained via casting temp and melt temp. Keep the melt at a reasonable temp and find a tempo that works.

I use a small fan to help cool the sprue after each pour.

Your alloy is fine. You are at a point where you need to adjust a few things in your routine to get good bullets. Keep at it and don't be afraid to try slower, faster, or colder. That alloy will cast well, you just need to find what it wants in that mould.

[Magana559]

There is more to the story, the other reason I posted was because of the bad fillout.....I'm talking partial boolits and what not. I'll post more pictures next time I cast to make things clear as mud.

[runfiverun]

some pewter ain't pewter.
quite often it's white metal or pot metal, not tin.
now that I have gone blank on what's in it, I can't tell you the name of what's causing the problem.
anyway it causes high surface tension and rounded edges in lead alloys.

[badbob454]

as was said get the mold hotter (consistent temp ) for complete fill out ,, aim for a little frost and back it down a few degrees. then your boolits will have a better fillout

[mold maker]

Either the range scrap or the WWs should cast good boolits, especially with the addition of a little tin. Your original intent of the alloy wasn't bad. I agree that the pewter, even if marked. may have had something else in it.
Before you do anything drastic, take a couple lbs and add more soft lead 50/50 to it. I'm betting that will dilute the contaminate to a workable alloy.
Using hard alloy except for high powered magnum rounds is not called for in hand gun rounds.
I use WWs or range scrap in 10mm, 44, and 45 almost exclusively unless pushing it to upper limits.

[Magana559]

I'm going to bite the boolit and buy some tin, add it to the mix and see what happens. I already tried casting at different temps with a nice warm mold.

I usually don't have trouble casting, I have cast about 10k pistol boolits and about 2k rifle boolits......This time I'm stumped.

[Vinne]

some pewter ain't pewter.

You're right there. I stick with the old fashion 50/50 bar.

[Larry Gibson]

I made a hundred pound batch 75 lbs range scrap 25 lbs of clip on wheel weights and added one pound of pewter to the mix.

Should have added a minimum of 2 lbs of tin to that 100 lbs of alloy. From the looks of the bullets and sprues there is a very high % of antimony in that range lead so you might want to go to 30 - 40% lead in the mix and add 2 - 3% tin to that.

As mentioned; some pewter ain't pewter so I also suggest sticking to pure tin or 50/50 solder which are known qualities.

Larry Gibson

[imashooter2]

LOL! Which pewter ain't pewter? There are things that look like pewter which aren't, but no genuine pewter is causing problems in casting.

[runfiverun]

100% hallmarked pewter is pewter [tin/antimony/lead and sometimes a little copper]
some things marked pewter or that looks and acts like pewter isn't, and especially pewterex ain't pewter.

[Magana559]

I should do some more casting here tonight, first thing I'm going to try is adding 1% tin then adding another 1%.
If that don't work I'm going to just get a analysis done so I know what is in the alloy....I don't want to play games on an unknown alloy.

[Magana559]

Added one percent tin to the mix and still had some wrinkles so, I added another percent....works nicely. Im guessing just needed more tin, Still a alloy that needs to run frosty (HOT!) but Im glad it works.

Im guessing these boolits are going to be very hard Im guessing my range scrap was very high in antimony. I really need to get an analysis on this lead.

[Larry Gibson]

Added one percent tin to the mix and still had some wrinkles so, I added another percent....works nicely. Im guessing just needed more tin, Still a alloy that needs to run frosty (HOT!) but Im glad it works.

Im guessing these boolits are going to be very hard Im guessing my range scrap was very high in antimony. I really need to get an analysis on this lead.

Add 25 - 30% lead to the range scrap to cut the antimony content before adding the 2% tin. You'll be surprised at the difference it makes.

Larry Gibson

[fredj338]

Either your clip ww had some zinc or your pewter wasn't pewter. That mix should cast really nice bullets. IMO< adding tin to an already messed up alloy is wasting tin. I would add more range scrap first, flux well with sawdust & try again.

[Magana559]

No zinc at all because I hand sort my wheel weights and I take my time to do it right.

Well today was a great day! I heated my mold and pot quite hot and it cast perfect now.

Tin absolutely did wonders on the 45 and 357 Lee molds, as for my NOE mold well, it worked great without the added tin.

Here are some pics of my 180gr gas check NOE mold.


101740
101741

[62chevy]

No zinc at all because I hand sort my wheel weights and I take my time to do it right.

Well today was a great day! I heated my mold and pot quite hot and it cast perfect now.

Tin absolutely did wonders on the 45 and 357 Lee molds, as for my NOE mold well, it worked great without the added tin.

Here are some pics of my 180gr gas check NOE mold.


101740
101741


Them some nice looking boolits Magana559.

[Magana559]

Thank you!