These molds go back to July 2007. I was just getting started learning about air rifles & pellets.
Machining
First, square up the vise on your milling machine.
Set up the blocks to machine. Move the cutter to the material until it touches and set the "Y"
axis zero point. Begin to feed into the material until the desired depth is attained.
I used scrap aluminum from previous work.
WARNING: WHEN CASTING LEAD, ALWAYS USE A WELL VENTILATED ROOM. LEAD FUMES ARE TOXIC
AND WILL MAKE YOU SICK
On "Y" jog in half the diameter of the lead pellet. You
can see it on the screen that I jogged .110" into the block. I machined a few a few
pockets .375" centers. Then move to the other block and do the same thing.
<First pictures shows the cutter and aluminum
block. I used a stone to hone the burrs from the edges.
I used our heat treat oven to melt the lead.
As you can see the oven gets pretty warm. Keeping the oven around 1000 deg. F. Once the
lead gets to temperature you can pour the lead into the mold. Use proper ventilation.
I used a vise to hold the two halfs together
with a pin in the middle to align. You can see the lead being poured and allowit to freeze.
Rotating the steel top of the mold, the 1/8" inlet holes will act as a cutoff,
leaving only the correct size pellet. Open the mold and remove the casted pellets.
I checked the size with a micrometer. Pending on how accurate the cutter is machined,
the correct depth in the mold will determine how the accurate the pellets will be.
You can size the lead pellets after to get a better diameter.