More nuggets of information. I tried dipping the corner of a mold, both steel and aluminum, in the melted lead. All I got was a freaking nightmare! The lead clung to the mold and refused to give way. And once, although the mold was closed when I put the corner in the lead, it came slightly ajar, getting lead in the fins. Brother what a pain THAT was to remove.
Now I either sit the mold on top of the pot or if an electric one sit the mold under the pot.
Either way, don't stop casting if the bullets don't look right, keep casting until you get it right. Don't waste the time, effort and energy to bring a pot to temp just to cast a few and give up. Like most things practice make perfect. Oh, dedicate an old all-cotton bath towel to casting. Fold it a few times and drop the RBs on it. Use a small nylon hammer/ dowel rod, or piece of hardwood to tap THE HINGE of the mold to make the bullets drop from the mold, NOT the blocks, or you'll ruin the mold. And de-grease the mold; I use alcohol.
Once more... if the lead/ mold are cold, the bullets wrinkle like those in your pics. If too hot they have a frosted look. Some say if cast too hot they'll be harder. I'm not an authority on that, I just segregate the culls in a corner of the towel and when cool to the touch gently drop them into the mold. Use Descretion here.
Just keep punching, you'll get there!
100% this, exact same experiences I have had and the exact same way I do it.
The only thing I can add is when I started I had pretty high reject rate but once you get everything figured out with a few sessions the culls drop to very few