HP CASTING VOIDS

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  • Last Post 24 November 2008
linoww posted this 19 November 2008

I was casting with a 454424 with a large HP made for my recently by Erik Ohlen.Upon inspecting a few while sizing i noticed the voids in the lower end of the cavities.Bases looked perfect and the HP pin was periodically dipped in lead to keep warm.All were dipper poured with ladle contact with a 'built up” sprue puddle area to get a bigger “head” over the pour.I seemed to be doing it correctly?I shot 10 of them for an initial trial and they shot fairly well considering the voids(3/4” at 20 and 4” at 150 out of a rifle in 45 Colt Cal.).I sectioned one of them for a closer look and see what i found.About 75% of them showed some sort of void similar to this one.

Interesting i thought

 

George Damron V

"if it was easy we'd let women do it" don't tell my wife I said that!

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Veral Smith posted this 19 November 2008

  Voids in bullets are almost always caused when the sprue hardens before the center of the bullet solidifies.  You can cure it by tilting the mold a little left and forward, filling the forward cavity first of coarse, and running a stream of lead into the sprue hole for maybe 2 seconds after it is full.  Move to the next cavity and repeat. - A stream of lead poured into the sprue hole of a cold mold with cold bullets in it, will melt down into the bullets a considerable distence and harden up as if it were normally cast.  This should give some idea of the melting force of running lead.  But it will be confined to a very small area around the sprue hole.

  This trick will help a little but not stop the porosity with pointy nose pour molds.

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linoww posted this 19 November 2008

Veral Smith wrote:   Voids in bullets are almost always caused when the sprue hardens before the center of the bullet solidifies.  You can cure it by tilting the mold a little left and forward, filling the forward cavity first of coarse, and running a stream of lead into the sprue hole for maybe 2 seconds after it is full.  Move to the next cavity and repeat. - A stream of lead poured into the sprue hole of a cold mold with cold bullets in it, will melt down into the bullets a considerable distence and harden up as if it were normally cast.  This should give some idea of the melting force of running lead.  But it will be confined to a very small area around the sprue hole.

  This trick will help a little but not stop the porosity with pointy nose pour molds.

I will cast with it like i do with your molds then.

Thanks for the help

George Damron

"if it was easy we'd let women do it" don't tell my wife I said that!

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RicinYakima posted this 19 November 2008

Geo,

I hate casting HP's, but have learned a few tricks, also. Hold the mould block over the pot tilted down and right. With the ladle, start the pour slowly to insure all the air is out around the pin and the alloy doesn't harden too quickly at the end of the pin. Then, like Veral, I continue to pour over the sprue hole for a second or two. Head pressure isn't a effective as liquid alloy running over the top of the mould.

HTH, Ric

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linoww posted this 19 November 2008

Surprisingly the longer 30 caliber HP's have have don't seem to have the void problem.I would have thought this blunt bullet to be the easiest to cast with.I think on this one it "may” have to do with the depth of the pin being very close to the base. i also thought the pour deflects directly off of the top of it and swirls in an odd manner and is cooling around the pin too early?

 

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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eko posted this 19 November 2008

Too deep of a pin and or too wide of a tip?  Let me send you another couple styles to try, Erik.  George, you got mail.

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CB posted this 19 November 2008

Look on th bright side, you've got a hollow hollow point!

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gunarea posted this 20 November 2008

Hey George

   This may be preaching to the choir, but here goes. When pouring in the molten alloy, do not pour straight into the cavity. Hit the side of the funnel and make the stream swirl like a toilet flushing. If this is already part of your technique,    never mind.

HTH

                                                                                    Roy

Shoot often, Shoot well

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linoww posted this 20 November 2008

Look on th bright side, you've got a hollow hollow point! Hardy harr harrr harr.. Funny!!!

 

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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linoww posted this 20 November 2008

gunarea wrote: Hey George

   This may be preaching to the choir, but here goes. When pouring in the molten alloy, do not pour straight into the cavity. Hit the side of the funnel and make the stream swirl like a toilet flushing. If this is already part of your technique,    never mind.

HTH

                                                                                    Roy

Still good advice though.

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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CB posted this 20 November 2008

linoww wrote: Look on th bright side, you've got a hollow hollow point! Hardy harr harrr harr.. Funny!!!

 

George

George, I'd sure like to know what you edited out of your post. :shock:

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runfiverun posted this 20 November 2008

i would say you are getting some cold cavitation there.

try heating your pins more.

or the pouring up one side of the mold and giving it a bit of jiggle as you go.

like the welders shake.

but i think like pat was saying if it is centered and at the base of the hole already there i bet it ain't hurting none.

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CB posted this 20 November 2008

R5R,

You give me too much credit. I was just having fun and being a smart ass.

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linoww posted this 20 November 2008

pat i. wrote: George, I'd sure like to know what you edited out of your post. :shock:

Top secret word strarting with “a” ending with “e” and a “whole” lot of letters in between<G>

 I solved my problem by bottom pouring and going very slow.Thanks all.

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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CB posted this 20 November 2008

Adorable???

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linoww posted this 20 November 2008

pat i. wrote: Adorable???

Exactly!!

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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linoww posted this 21 November 2008

Got it all cured.I either bottom pour very slow(Ed Harris' way).or ladle pour in a different manner.When ladle-ing i fill the cup up abut 3/4 full and pour like Veral recommended(similar to Ric's as well) I let all of the metal empty from the ladle into hte tipped cavity and presto nice perfect bullets.

Thanks to all who helped me though it especially Pat I. for his thoughtful insight.

 

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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CB posted this 21 November 2008

don't mention it

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hunterspistol posted this 22 November 2008

Yes, that's exactly it-you can heat the mould and sprue cutter by overpouring the top of the mould. Another thing you can do(this is standard Lyman procedure) is to hold the alloy in the mould for a minute. Heats the mould, solidifies the alloy. Leave the pin in until you get ready to pop the mould open, then twist. By holding everything together when ladle casting you do a heat exchange.

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linoww posted this 24 November 2008

Tested “good” bullets cast with ladle this weekend.Load was 7.2 of B-Eye and a Fed LP primer.Rifle was Winchester 94 Legacy 24” barrel cal. 45 Colt Rifle.Scope was 1.5-6X cheap Simmons.Range was my 150"ish” range at the cabin.Loaded 30 to test,first group was about 2” tall and about 4” wide.Re rested the gun with bag at front of fore end and shot the three following groups.It says alot about the quality of Erik Ohlens HP conversion.

 

George Damron

"if it was easy we'd let women do it" don't tell my wife I said that!

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linoww posted this 24 November 2008

hunterspistol wrote: Yes, that's exactly it-you can heat the mould and sprue cutter by overpouring the top of the mould. Another thing you can do(this is standard Lyman procedure) is to hold the alloy in the mould for a minute. Heats the mould, solidifies the alloy. Leave the pin in until you get ready to pop the mould open, then twist. By holding everything together when ladle casting you do a heat exchange.

With large pin HP's running alloy through it without the pin in helps get it pretty hot pretty fast .After a few pours it runs straight though and your first “real” bullet is a keeper --sometimes--

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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