Might have learned something about using Lee molds

[David2011]

I love my iron and steel molds and have tolerated the aluminum ones for years. Things might have gotten better tonight. I've always fought pace versus mold temperature with the aluminum molds. The 30+year old RCBS furnace drips a little so I wanted to totally drain it tonight to clean the rod and nozzle.

I have six cavity Lee molds for a couple of boolits used in pistol matches where large volumes of boolits are consumed. I've always poured a full stream into the aluminum molds the same as I would for cast iron and steel molds. It's always been hard to get the melt to pile up on the sprue plate using the aluminum molds. The melt just seemed thinner pouring it onto the aluminum sprue plate. I've settled on a pace of pour, let the sprue cool for 10 seconds, dump, let the opened mold cool for 20 seconds and repeat so 1-1/2 pours/minute or so was the average. The mold is the 358-158-RF Flat Nose which leaves almost as good of a hole as a wadcutter but will work at .357 Magnum loads.

As the melt got low in the pot and head pressure diminished the silver stream got smaller. The runaway melt on top of the sprue plate became much more controllable and piled up more like it does on steel sprue plates, stacking up higher but smaller diameter. I decreased the cooling period between pours as I could tell the mold was cooling off until, with a very small stream, the extended cooling period was no longer necessary. I didn't count the time to pour but it was slow, probably 2-2.5 seconds per cavity for a 158 grain cavity where I had been filling the 6 cavities in 4-4.5 seconds with half a pot of melt (22 lb pot). There's an old GraLab darkroom time sitting on the casting bench that really helps regulate pace. The mold had to be kept hot to avoid wrinkles but the pace was greatly increased even though it was taking much longer to fill each cavity. The boolits were looking great and it was the highest quality, lowest effort casting I've ever done with a Lee mold. Next time I cast using one of the Lee six-bangers I'm going to regulate the stream down from the outset and see if the results are repeatable.

Even with the slow fill rate (slower is faster) I cranked out 450 boolits in about 90 minutes.

David

[runfiverun]

yep+.
I have my 20 lb pot turned down to a dribble, and I cast with my rcbs 2 cavity 22 cal mold with it at a leisurely pace and turn out fine boolits.

[GhostHawk]

Maybe that is why I like my Lee Molds, I use a dipper,

[Shiloh]

Every pot seems to be a little different. I look for a steady stream with no drips, opening as the pot empties. I also never have the pot more than 3/4ths full. Be sure and keep the nozzle free from debris and cast away. Develop a routine that works for you.

SHiloh

[chajohnson]

With Lee 2 or six cavity molds I've always found that alternating 2 molds works best in terms of both pace and temperature for good fill out., at least in pistol calibers from 38 thru 45. Additionally, it results in a pile of bullets with few rejects and fairly consistent size and weight. The downside is that it empties a 20 lb Lee dripomatic in a hurry. Trying to keep in full for good flow and constant temperature was a challenge. I had an old XX Lyman furnace with a damaged leg that I wasn't using. I mounted it above the Lee as a, "pre-melt," furnace. This allowed me to keep the Lee furnace at a good temp with good flow. However, a good all-day casting session can be really exhausting, but results in a full seasons worth of handgun fodder.

[mongoose33]

<Thinking out loud>

Hard to believe I'd be the first to think of this, but given the relationship between head pressure and bullet fill-out, has anyone ever set up two Lee (or similar) pots, one above the other, where the top drains into the bottom one, and the spout handles are connected such that as the bottom one drains out into the molds, the top one drains into the bottom one, replacing the lead lost to the mold, and keeping the amount of lead in the bottom pot at a constant level?

[runfiverun]

yep...
do a search, you should find some good pictures.

[mongoose33]

yep...
do a search, you should find some good pictures.

Any idea what search terms might work? I've tried several combinations, no joy.