Cast method

[Drm50]

I gather that a lot of guys are having trouble shaving cast bullets
if you cast your own I can tell you a little trick I use. I'm into
quality not quantity, so this is not for progressive crowd. When you pour your bullet let moulten lead flow in stream from ladle
into mould. This will cause bullet to have a rounded heel. If you
put ladle or nozzle of bottom pour pot, against spru , you base will come out with sharp ,square, heels.

 

[colt_saa]

Unless I am misunderstanding you, It sounds like you are suggesting that the caster NOT fill the mould.

If the edges are not full and sharp and identical to the mould, the projectile is bad.

How do you know where lead is and isn't? How can weight be properly distributed for accuracy?

If you want a bevel base projectile, buy a bevel base mould.

 

[STCM(SW)]

I keep the heat a little higher and only use a ladle plus the right alloy(Lyman #2) with enough tin to have clean sharp bullets.

 

[rsrocket1]

If the edges are not full and sharp and identical to the mould, the projectile is bad.

If you want a bevel base projectile, buy a bevel base mould.

+++

You definitely don't want a rounded base from a sharp base mold. You don't have to sacrifice quality when making lots of bullets.

Shaved lead comes from either not expanding the case enough to start the bullet or you are trying to close the case mouth with a seat/crimp die while continuing to seat the bullet deeper.

I cast my bullets by the thousands and load them by the hundreds, usually 100 at a time several times a week, but I never get shaved lead even on a progressive.

If the bases of my bullets drop out rounded, they immediately go back into the pot. That usually comes from not enough lead in the sprue. While the lead solidifies, it draws more metal from the sprue. If the sprue is too cold or not filled, the bases can't fill out and wind up rounded.

35 pounds of powder coated 9 and 40 bullets ready for the progressive loader. All with sharp bases.

 

[fredj338]

+++

You definitely don't want a rounded base from a sharp base mold. You don't have to sacrifice quality when making lots of bullets.

Shaved lead comes from either not expanding the case enough to start the bullet or you are trying to close the case mouth with a seat/crimp die while continuing to seat the bullet deeper.

I cast my bullets by the thousands and load them by the hundreds, usually 100 at a time several times a week, but I never get shaved lead even on a progressive.

If the bases of my bullets drop out rounded, they immediately go back into the pot. That usually comes from not enough lead in the sprue. While the lead solidifies, it draws more metal from the sprue. If the sprue is too cold or not filled, the bases can't fill out and wind up rounded.

35 pounds of powder coated 9 and 40 bullets ready for the progressive loader. All with sharp bases.
]

Bases are everything on any bullet. I have flat base & bevel base molds. I cast by hand with a bottom pour pot or on my magma. Pour rate will give you sharp bases on a well vented mold. I do also pressure cast, holding the mold to the spout, for troublesome molds.
You can get lead shaving from an ill fitting seating punch. I' having that problem with a new rnfp for my 45. It will cant if the bullet isn't really straight during seating. This slows my 650 down quite a bit, so gotta exp with seating punches.

 

[Mad_Charlie]

"Bases are everything on any bullet."

Absolutely correct, I would only add that CONSISTENT bases are everything on any bullet, and it is difficult to achieve consistency when trying to pour round based bullets with a flat based mold.

They may look the same, but how can you be sure?

 

[Drm50]

Bevel

The bevel with flat base mould only happens when I pour metal
that is 9:1 , Lead/ Tin. I came across this by accident. You pour
metal into mould, with mould horizontal, filling mould. I don't
know if it is caused by air or the alloy or both. I started doing it
on purpose for 11 mm Mauser, 43 Spanish, 455 Elley. Haven't
had any problem with voids,maybe because of large bullets?

 

[Doubless]

I ladle cast rifle bullets and I bottom pour handgun projectiles. Handgun bullets don't have to be as weight compliant as rifle bullets do.

When I ladle cast, I start with the mould sprue plate perpendicular to the ground. I put the ladle spout into the sprue hole tightly and rotate both 90 degrees. When metal flows from the sprue hole I slack off on the pour and leave an ample sprue and allow the sprue to freeze.

I have never been a fan of using the bottom spout of a pot to cast rifle projectiles. I have experienced too many failed bullets because as the column of metal in the bottom pour pot lowers the bullets get lighter. I can't explain it, but I have experienced it. I guess it happens with the handgun bullets too, but again: they seem to be a bit more tolerant of weight differences than rifle bullets are. My H&Gs typically cast to within a grain if I do my part, and often half of the eight or ten from one pour will weigh within a tenth. Close enough!

 

[Drm50]

Flux

If bullet is getting lighter as you go, in bottom pouring pot, your
Bullet metal is statifying. The lead is the heaviest, will be on bottom, the other metals will be stacked in layers according to
weight. You have to constantly flux your pot to avoid it.

 

[rsrocket1]

If bullet is getting lighter as you go, in bottom pouring pot, your
Bullet metal is statifying. The lead is the heaviest, will be on bottom, the other metals will be stacked in layers according to
weight. You have to constantly flux your pot to avoid it.

Please no disrespect and I am saying this with a big smile on my face, but where did you get that logic?

Alloy metals are like Kool-Aid. If you leave Kool-Aid alone in the container, the sugar does not stratify and sit at the bottom of the pitcher.

You flux a pot of lead to a) get the impurities out and b) to reduce the oxides back into metal, not to blend the layers of metal. Stirring the bottom of the pot is a good practice because it gets junk trapped down there and brings it to the surface so you can scoop it out.

Here's a great book you can download and read for free:
From Ingot to Target:
A Cast Bullet Guide for Handgunners

Get the PDF version and keep it on your tablet or print it out for reference. It does get pretty technical so you can read or skip as much as you want. The guy knows his stuff.

 

[fredj338]

If bullet is getting lighter as you go, in bottom pouring pot, your
Bullet metal is statifying. The lead is the heaviest, will be on bottom, the other metals will be stacked in layers according to
weight. You have to constantly flux your pot to avoid it.

Agree, flux more often, never let the pot get below 1/2 full.

 

[Drm50]

Alloys

I'm not a metal expert, but I can tell you with a big grin. That
there is a big difference in the melting point of a prepared alloy
And a pot full of questionable lead and unknown metals that
can be present. To form the alloy you have to reach temps of
1100-1200, you ain't going to do that in electric pot. When you
melt "junk" lead from different sources at electric pot temps
the metals will statify. Fluxing the metal will release the metal trapped in the dross, back into the melt. Stirring with flux keeps
a more uniform mix, it's really not a alloy because it never has
Reached temps high enough to alloy. I have been reading books
on casting for 50yrs, I've not had any problems. Try reading the
old Lyman and Ideal books on the subject.

 

[fredj338]

I'm not a metal expert, but I can tell you with a big grin. That
there is a big difference in the melting point of a prepared alloy
And a pot full of questionable lead and unknown metals that
can be present. To form the alloy you have to reach temps of
1100-1200, you ain't going to do that in electric pot. When you
melt "junk" lead from different sources at electric pot temps
the metals will statify. Fluxing the metal will release the metal trapped in the dross, back into the melt. Stirring with flux keeps
a more uniform mix, it's really not a alloy because it never has
Reached temps high enough to alloy. I have been reading books
on casting for 50yrs, I've not had any problems. Try reading the
old Lyman and Ideal books on the subject.

I think this really only applies to something like antimony, which has a high melting point. You can certainly alloy scrap, pure & tin in an elec pot, their individual melting temps are all well under 900deg. When antimony is alloyed, it readily blends with other metals. Why I have always sought Lino or monotype for alloying with other metals.
You are correct about fluxing. It should be done often to keep the alloy together. When actually casting, I just stir often with a wooden paint stick.

 

[Snapping Twig]

Pour your bullets hot and fill the mould. A perfect base is probably the single most critical thing about a bullet.

Slightly flair the case mouth before seating and all lead shaving will be eliminated.

 

[venomballistics]

In that most pistol bullets are used to make holes in paper at or below 25 yards, we might be horse whipping the OP a little hard.

The base is critical.
everything about it can make or break it. It must leave the muzzle with as close to a perfectly clean break as possible.
If it fails to do this, the gasses released for that fraction of a second to one side of the bullet will impart a small amount of force which takes it off intended course.
this alteration may just 10 MOA, which you will not see much of at the usual ranges. It will limit your total useful range.
2.5 inches at 25 yards is not too bad.
10 inches worth of miss at 100Y ... you can and should do better.

Complete fillout of the base is very important for this reason.
For similar reasons, you should check your sprue plate from time to time.
It can be lifted from the block by the lead filling in below it under certain conditions. This causes a crooked base, which will be as much of a random number generator as an ill filled heel.

 

[fredj338]

Something I have had to do on a couple finicky molds is break the top edge of the mold blocks ever so slightly to provide a cent line under the spru plate. Seems to help fill the bases better on those particular molds.

 

[Doubless]

I'm not a metal expert, but I can tell you with a big grin. That
there is a big difference in the melting point of a prepared alloy
And a pot full of questionable lead and unknown metals that
can be present. To form the alloy you have to reach temps of
1100-1200, you ain't going to do that in electric pot. When you
melt "junk" lead from different sources at electric pot temps
the metals will statify. Fluxing the metal will release the metal trapped in the dross, back into the melt. Stirring with flux keeps
a more uniform mix, it's really not a alloy because it never has
Reached temps high enough to alloy. I have been reading books
on casting for 50yrs, I've not had any problems. Try reading the
old Lyman and Ideal books on the subject.

That would be all well and good except for one thing: I am using linotype that has been previously alloyed. I think that pretty much negates your argument about alloys separating in the pot and stratifying... I am sorry, sir, but it just doesn't happen that way.

 

[mikld]

I have "pressure poured" with my bottom pour pot and with my Lyman ladle, but that's not the key to good bullet "fill out". Proper/good mold temperature and alloy temperature are much better factors to achieve good square bases from any mold. The only time I've heard the term "shaving" of lead bullets is scraping/shaving the side of the bullet when seating in the case or from a misaligned cylinder (out of timing)...

 

[jtcarm]

Uh, yeah, what everyone else said.
I've been loading Hornady Cowboy bullets lately & have to flare the case mouth extra since they're so soft.

I've always used the method recommended by Veral Smith at LBT: keep the mold slightly away from the pour spout and run it over a bit. According to Veral, the bullet contracts as it cools and running slightly over gives it more alloy to pull in as it cools.

It's always worked for me.

 

[leathermech]

Referring to the original question, I can’t imagine why you’d want to jury a rounded based bullet. I also can’t imagine being held account for some of the “good ideas at the time” I’ve chased over the years. The base of the bullet is the part pushed by the propelling gasses. When imperfect, that last pat on the bottom will return the same results as a cut in the crown of the barrel.

Here’s a game. Take a file and cut a little flat on edge of the bullet base. Load a few lots with perfect bases and a few with the flats. You might try them at 50 yds or farther. See for yourself if it matters.

You might consider a bevel based mold?? If you can’t find what you want, there’s several outfits on the interweb that will cut a mold to your specs. Put “Custom Bullet Mold” in the googlizer then get out your credit card.

As for the melt and how bullets drop at inconsistent weights, buy a thermometer and don’t drop your cut sprue or bad bullets back in the pot during your casting run. I took several years to figure out melt temp is the remedy for inconsistent cast weights in my shop.

I’ve used the same cheap Lee bottom-pour for two decades, with a few repairs. I’ve raised the pot with wooden spacers to accommodate the knob of hollow point and hollow based molds. I put my mold on a hot plate to heat it while the pot melts then hold the mold off about ½ inch from the spout. I seldom cull incomplete or wrinkly fills.