Hi, SA Shooter!
Welcome to the wonderful world of bullet casting!
Just a few tips for better results with your cast bullets:
1. scrap lead is fine for most pistol bullets at moderate velocities. The more critical your needs (accuracy, high velocities, expansion, etc) the touchier the alloy and bullet quality.
2. The wrinkles you get are from either the mold not filling out properly, the alloy/mold temperature too low, or improperly fluxed alloy. YES! you need to flux your bullet melt often when casting. That crap you skim off the top of the melt contains the vital tin needed for the alloy to flow properly. Toss out the tin when you skim, and the bullet quality suffers. Also, by removing the tin, and leaving only an antimony/lead mix (common in wheel weights), you get a bullet that exposes lead crystals and antimony in a matrix. Almost a garantee that you will get leading!
3. Most casting authorities recommend frequent fluxing of your mix IN THE CASTING POT every 10-15 minutes. It will assure that the melt stays uniform, and removes impurities (slag, contaminants, etc). Fluxing is easy: just drop a corn kernel sized piece of parafin, old bullet lube, candlewax, etc into the pot, and stir it your dipper, scooping it into and throughout the mix from top to bottom. Repeat. Skim off the crap that floats up.
4. Leading almost always results from too soft an alloy, too hot a load, or undersized/oversized bullets that don't fit your barrel groove diameter. For revolvers, tight chamber throats can also give leading problems. You need to experiment by changing only ONE variable at a time to see what effect it has. I would start by switching powders. WW296, H110, IMR 4227, and H2400 are fine for heavy magnum-tuype loads, but they burn slower to give the higher velocity, and can be notorious for causing barrel leading.
5. Firing a few JACKETED bullets after each session with cast slugs is a good and easy way to clean most of the lead out of your barrel.
Good luck! Let us know how you make out.
John