So, I came up with an interesting way to slug the barrels of my pistols.
Next time you cast, bring a couple FIRED/CLEANED cases out for the caliber you are going to slug. This kind of only works for pistol caliber or straight wall cartridges.
Once your pot is hot, heat up the cases in the pot until lead doesn't stick and then fill it. Once it cools down, use a bullet puller to get the slug out. Then when you want to slug the barrel, lube that slug with some oil and pound it from the end of the barrel through to the chamber. Easy. And you can make a couple in various calibers next time you cast for the next couple guns you buy...