Lee Six cavity 40 S&W mold.

[45-70 Chevroner]

My neighbor came over with his new 40 S&W mold and wanted me to help him with it. He said he could not get it to make good boolits. I ask did you clean it first, he said no. I cleaned it up with dish soap and Ajax cleanser. Preheated it and the first 6 were winkled so I dipped it in the melt for about a minute and after all was said and done we had 540 boolits with no wrinkles and perfectly filled out. Good day casting.

[Tatume]

Those Lee six-cavity molds are really good!

[captaint]

One good trick I learned here is to start the 6 cav's by just filling the first 2 or 3 holes closest to the sprue plate hinge. Then as the mold heats up we can start filling more cavities and not break the handle opening the sprue plate. Great idea. Mike

[Tatume]

My opinion, the most important step is to get the sprue plate hot, and keep it hot. I overpour and let the excess lead run back into the pot. You could do the same with a bottom pour pot by letting the overflow fill an ingot mold. The idea is to keep the sprue molten as long as possible, thereby heating the plate, and at the same time allowing the bullet bases to completely fill.

When the mold and sprue plate are good and hot, it will be easy to open the mold.

[trixter]

Why not just use a hot plate?

[Tatume]

Why use a hot plate? Over-pouring gets everything hot right away, and doesn't require pulling out another piece of equipment. Further, over-pouring is the best way there is to get good, sharp bases. I do it on every pour.

[45-70 Chevroner]

Although I use a hot plate ( just at the start ), I agree with Tatume, over pour has worked for me for over 40 years. I have tried other methods like pressure fill and small sprue. Large sprues work best, like as much lead on the sprue cutter as what is in the mold, although that is not always possible with one and two cavity molds. I always slip the sprue back into the pot while the next pour is getting read to cut.

[Shiloh]

Yep,
A lot of new mold problems disappear with a thorough cleaning.

Shiloh