HP woes

[sergeant69]

i was casting these a coupla years ago and quit due to back surgery, and had the same problem and didn't get it resolved. casting .44 HP in a lyman mold 250 gr GC. problem is its not filling out the mold. i am casting up to 900 deg, top pour from a Lee magnum furnace, using a one lb and a 1/2 lb ladle. i have poured straight down into the hole, from the side, over run the mold w/a full ladle full, you name it. the mold is clean etc inside. have gotten the mold/lead so hot it takes a timed 20 seconds to harden the sprue. am at a loss. any help appreciated. thanks.

[MtGun44]

Need more heat in the pin. One way is to cast VERY fast, some find it necessary
to keep a propane torch idling neaby and heat up the HP pin (assuming this is a
single cav with separate pin) just before inserting into the mold.

Bill

[sergeant69]

wow, who'd a thunk it. yes, its a single cavity w/ seperate pin. thanks

[plainsman456]

Looks like just a tad cold on the mold to me.
When i got mine,it is a 4 hole mold, i thought that i was going to ruin it by getting it that hot.

But it started casting like a charm once it got to it's happy place.
had to use a deer skin and welder's glove just to keep from burning my hand.

Until i got it the only hp mold i had was an old lee with the pin fixed on the bottom.It being aluminum not brass.

[Trey45]

I dip the pin in the melt for a 15 count to heat it, a propane torch will work too, but I figure since the lead's already hot and sittin' right in front of me, why not use it to heat the pin. I betcha heatin' the pin solves that incomplete fill out issue.

[sergeant69]

ok, gonna try all that. i thought the pin was hot enough cause its hot to the bare hand holding it by the wood knob. but if its not...its not. can't try it tomorrow as babysitting a 2 yr old. by myself. all day. HELP!! told her mom i was gonna teach her to cast. can't say here what she said. so...soon gonna have another go at it. thanks.

[MakeMineA10mm]

I've got the same mould. Extra tin helps, and keeping the pin hot helps, but the bottom line is casting FAST! There is no substitute for that.

I'd be nervous running my lead that hot. Is that number true? (Did ya have a thermometer?). I never get my pot above 800, and I cast at around 700-750 degrees.

[Larry Gibson]

I have the same mould also and cast good bullets. A proper alloy with sufficient tin is needed as mentioned. I also cast at 725 - 750 degrees. Dipping the pin to keep it hot works but I prefer a simple set up with a propane torch. adjust the flame of the torch to keep the pin just hot enough given your casting speed and the ambient temp of the place you are casting at.

BTW; just so some one won't get excited the idea comes from the NRA's cast bullet handbook. The picture of my set up shows a .30 cal pin but the .44 pin works as well in the wire holder.

Larry Gibson

[sergeant69]

I've got the same mould. Extra tin helps, and keeping the pin hot helps, but the bottom line is casting FAST! There is no substitute for that.

I'd be nervous running my lead that hot. Is that number true? (Did ya have a thermometer?). I never get my pot above 800, and I cast at around 700-750 degrees.

yes, that was a thermometer temp.

[sergeant69]

LARRY... thats a hot set up (pun intended). thanks for the tips. gonna give it a try next session. thanks.

[cbrick]

sergeant69, thought I was looking at my first HP casts.

Yep, pin temp is the key. To qoute my favorite author, Glen Fryxell " A hot HP pin is a happy HP pin". Molten alloy hits that cold pin and sucks the heat right out of the alloy & it solidifies before it can fill out the cavity just as in your pictures. As you can see from your bullets, the colder the pin the worst it gets. The pin has very little mass to hold heat compared to the mass of the blocks and will cool much faster. Keep the pin in the blocks, the blocks closed and full as much as possible. If your casting pace doesn't keep the pin hot enough use the torch as Larry suggested.

900 degrees? Are you kidding us? 900 degrees?

I couldn't tell you even IF my pots would get to 800 degrees & don't intend to find out. Good thing you don't have any tin in your alloy. Tin looses it's ability to reduce surface tension by inhibiting oxidation at 750 degrees, past this temp tin itself oxidizes much faster & the hotter the alloy the faster tin will oxidize.

Rick

[Shuz]

900 degrees? Are you kidding us? 900 degrees?

I couldn't tell you even IF my pots would get to 800 degrees & don't intend to find out. Good thing you don't have any tin in your alloy. Tin looses it's ability to reduce surface tension by inhibiting oxidation at 750 degrees, past this temp tin itself oxidizes much faster & the hotter the alloy the faster tin will oxidize.

Rick[/QUOTE]

Rick, FWIW, I cast at a measured 750 to 800 deg with a 1 to 2% tin alloy. I eliminate the tin or lead oxidization, by loading the top of my pot with kitty litter. Naturally, I bottom pour. I think this is the biggist advantage to a bottom pour pot.

[largom]

I have an old Lee 4 lb. pot that I keep FULL of alloy. I placed a piece of aluminum over the pot with a small hole in the center which will hold the hollow point pin. I keep this pot around 750 deg. As soon as I remove the hollow point pin from the mold I place it into this pot of alloy. This keeps my pin hot while I cut the sprue and drop the boolit. This also keeps the pin from over heating.

Larry

[fredj338]

I don't keep the pin hot, just get it to temp & start casting, keep casting. I have the same mold & casting @ 750deg or so, get perfect HP after 4-5 w/ preheated mold & pin. I use a 20-1 or 25-1 or 50/50 CWW & lead with same results. I do use a BP pot & pressure cast though, seems to give better mold fill-out for me.

[45-70 Chevroner]

I was just testing. I couldn't get a reply for any thing to work this morning.

[cbrick]

Rick, FWIW, I cast at a measured 750 to 800 deg with a 1 to 2% tin alloy. I eliminate the tin or lead oxidization, by loading the top of my pot with kitty litter. Naturally, I bottom pour. I think this is the biggist advantage to a bottom pour pot.

Shuz, here's a tip for you. Yes, the tin in contact with air on top of the pot will oxidize but this is not where tin's biggest benefit is. The alloy in the stream from your bottom pour into your mold is also in contact with air. Starting about 750 degrees tin begins loosing it's ability to lessen the surface tension by limiting oxidation. The hotter past 750 the more tin is inhibited.

Even if you have a mold that needs to be at 500 degrees to cast well a pot temp of 700 (well under 750) is still well past the desired mold temp, it will get & keep your mold plenty hot.

You are of course free to cast as you wish but that is the metallurgy of Pb/Sn alloys.

Rick

[sergeant69]

sukkccess!! i like the torch/pin idea but didn't want to use up my propane supply as per LARRYS set up. so....i brought in from the yard my old smelting pot and wrapped a wire over it similiar to the torch set up and now just drop the pin in the holder and it self dips into the hot lead. insert pin into the mold, pour, take out pin, insert into wire holder, drop bullet, start all over again. works great. thanks for all the ideas guys!!