Today I decided to give my newly acquired equipment a go and cast some bullets using my Lee production pot and two of my aluminum Lee molds (.452 200gr and .459 500gr)... and I've got a few skin burns to prove it, lol! (due to a few stupid beginner's mistakes) 
So, I melted a full pot of wheel-weights (turned out great), did the flux procedure and skimmed all the junk off the top, then ended up with a pot full of clean lead. I preheated the first mold and began casting, soon reaching a point where all bullets came out perfect. I made approx 60-70 bullets that way with no quality issues and nothing going back to the pot.
But then... I melted some more wheel weights, fluxed & removed the impurities once again and started re-casting again (I temporarily cranked up the temp to melt, then brought it back down like it was before). The molds were still hot, as the procedure only lasted a few short minutes. All my bullets that followed were wrinkled as heck and pretty much 80% of them had to go back to the pot to re-melt. I played with the temperature dial and eventually it started casting a little better, but still not like it used to on the first try (after the first melting). Why is that?
Personally, I think it's something stupid like maybe figuring out some sweet spot on my melter's temp gauge... but I couldn't figure it out today and it was very frustrating to say the least, as I could've easily made 300+ perfect bullets today, but ended up with 100-something, as the rest was wrinkled or had little bits missing on them and had to go back in. Thanks in advance for any insight you may have...

P.S. I know that some wheel weights are made of something different than lead and that they don't melt as fast (and should be removed from the pot ASAP before they do melt & contaminate the alloy). I had only one of those weights that didn't melt and I removed it promptly... so I assume the rest were pure lead.
.
So, I melted a full pot of wheel-weights (turned out great), did the flux procedure and skimmed all the junk off the top, then ended up with a pot full of clean lead. I preheated the first mold and began casting, soon reaching a point where all bullets came out perfect. I made approx 60-70 bullets that way with no quality issues and nothing going back to the pot.
But then... I melted some more wheel weights, fluxed & removed the impurities once again and started re-casting again (I temporarily cranked up the temp to melt, then brought it back down like it was before). The molds were still hot, as the procedure only lasted a few short minutes. All my bullets that followed were wrinkled as heck and pretty much 80% of them had to go back to the pot to re-melt. I played with the temperature dial and eventually it started casting a little better, but still not like it used to on the first try (after the first melting). Why is that?
Personally, I think it's something stupid like maybe figuring out some sweet spot on my melter's temp gauge... but I couldn't figure it out today and it was very frustrating to say the least, as I could've easily made 300+ perfect bullets today, but ended up with 100-something, as the rest was wrinkled or had little bits missing on them and had to go back in. Thanks in advance for any insight you may have...
P.S. I know that some wheel weights are made of something different than lead and that they don't melt as fast (and should be removed from the pot ASAP before they do melt & contaminate the alloy). I had only one of those weights that didn't melt and I removed it promptly... so I assume the rest were pure lead.
.