Compression Bullet Casting

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Idaholewis

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Jun 30, 2017
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4,959
I posted this under the Paper Patch thread, But felt it would make a Good Thread of it’s own. This is one of the More important Steps in my Casting to Achieve OPTIMUM Fillout, Something i learned through Trial & Error. If there is enough interest in Seeing exactly how i do this, I will set up my Little Video Camera and Run a Short Youtube Video Showing the process

Compression Casting is when you Fill the Mold, And you continue to Hold the mold under the Stream of Lead, even Though the Mold is Full, The Weight of the Lead is “Pushing Down” in the Cavity, it’s called Compession Casting. Certain Molds React Very well to it, and some Not so much

Notice the Shape Of the Pour Spout? Be it Ladle, or Bottom Pour Pot, They have a Slight Taper, Now look at the Hole in a Sprue Plate, it is “Dished“ Shaped, These 2 Fit eachother perfectly. You want to “Marry“ the Spout up with the Sprue Plate, Then Fill the Mold, Holding them together for a Few Seconds after the Mold has Filled.

PRACTICE, PRACTICE, PRACTICE, And Be Consistent

You will learn exactly how long it Takes to fill your Mold. Lets Say it Takes 2 Seconds to Fill, Hold Compression for 3 Seconds, So it takes 5 Full Seconds per Cast Bullet (That is a Just a Close example, You need to Tinker around here til you find what works Best for your Mold)

Compression Casting is where you will get OPTIMUM Mold Fillout :lewis:
 

Bruce Mattes

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Feb 15, 2020
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511
So this should work with a Rowell #1 bottom pour ladle holding a pound of lead, such as the ones that Rotometals sells?

This is how you are getting those perfectly square bases, that and the correct temperature for the lead?

How often do you flux?

I think I am going to dispense with the electric ladle furnace, and simply purchase a new Lodge 7 quart flat-bottom Dutch oven. The one with the wire bail handle with the twisted wire grip.

It should easily hold 40 pounds of melted lead.

Along with the analog lead thermometer that Rotometals sells.

Then I can purchase 99.9% lead in the 5lb bars, also from Rotometals.
 
Last edited:

Idaholewis

Well-Known Member
Joined
Jun 30, 2017
Messages
4,959
So this should work with a Rowell #1 bottom pour ladle holding a pound of lead, such as the ones that Rotometals sells?

This is how you are getting those perfectly square bases, that and the correct temperature for the lead?

How often do you flux?

I think I am going to dispense with the electric ladle furnace, and simply purchase a new Lodge 7 quart flat-bottom Dutch oven. The one with the wire bail handle with the twisted wire grip.

It should easily hold 40 pounds of melted lead.

Along with the analog lead thermometer that Rotometals sells.

Then I can purchase 99.9% lead in the 5lb bars, also from Rotometals.
The Rowell is Different, and would be impossible to Compression Cast with (I have a Rowell) The Rowell has a Pour type Spout That you could Not “Marry up” to the Sprue Plate Hole, The Rowell is simply designed to Pour.


The Lyman, and RCBS on the other Hand have Rounded Pour Spouts that Match the Bullet Molds Sprue Plate Hole, Allowing you to “Marry“ them up, and Compression Cast

 

Idaholewis

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Jun 30, 2017
Messages
4,959
Here we go, i went and took some pictures. Even though I don’t use Ladles, I Stil have 2 of them :) I can use them, and get decent Results, I just prefer my Bottom Pour Pots

Here are my Lyman (Left) and Rowell (Right) Ladles, Note the Rounded Spout on the Lyman


Here is One of my Buffalo Arms Molds, Note the “Dish” Shape of the Sprue Plate Hole (All molds, Regardless of Brand look very Similiar)


Now here is my Lyman Ladle in the Mold Sprue Plate Hole, Note how they ”MARRY UP“ Perfectly? This Allows you to “Compression“ Cast :lewis: Fill the Ladle, Turn the Mold up Sideways, “Marry up” the Ladle Spout to the Sprue Hole Turn back and Fill the Mold, When full, You want to HOLD The Ladle for 2-3 Seconds, Allowing the Weight of the Lead/Alloy remaining in the Ladle to “PUSH DOWN” Holding Pressure in the Mold Cavity. This is Called “Compression“ Casting


Now look at the Rowell, It is impossible to “Compression“ Cast with these Types of Ladles, These are Designed to Pour. Simply Fill the Ladle, Pour the Mold Full. Some Folks Allow the Rest of the Lead/Alloy to Pour over the Sprue Plate and back in the Pot.
 

Bruce Mattes

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Joined
Feb 15, 2020
Messages
511
The Rowell is Different, and would be impossible to Compression Cast with (I have a Rowell) The Rowell has a Pour type Spout That you could Not “Marry up” to the Sprue Plate Hole, The Rowell is simply designed to Pour.


The Lyman, and RCBS on the other Hand have Rounded Pour Spouts that Match the Bullet Molds Sprue Plate Hole, Allowing you to “Marry“ them up, and Compression Cast

Thanks for the info
 

Boommeup

Member
Joined
May 19, 2020
Messages
18
I was making 22 caliber hollow points the other day, on a pro-melt. I never really tried the compression pour cuz I thought you needed it ( the mould) about an inch away and leave a good puddle on top of the spru cutter. For drawing in lead as it contracts. Well I changed up how I was pouring by fitting up tight with the nozzle. Really worked very well! But! I did notice if you don’t have your mould matched up tight with the nozzle molten lead WILL flow rather fast off the top of your spru cutter! Like Lewis said practice, practice, practice.
 
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