A torch will work, particularly if you cut off " corners". However, its time consuming, and you will go through a lot of gas. You have to weigh the costs.
Melting in a large pot is OKAY, IF YOU ALSO HAVE a large source of heat. That huge block acts like a heat sink, sucking the heat away from all but the contact surface between the block of lead and the container, or torch flame. My first " ingots" were made by drawing finger wide grooves in soft dirt, the day before the casting. We let the dirt dry out in the sun and bake the next morning before we poured lead into the grooves. The sticks cooled quickly and were easily removed with pliers. We threw them on the patio and turned the hose on them to cool them sufficiently to handle. The grooves in the flower bed were reused over and over again. I won't say the sticks of lead were pretty, but they melt fast when fed into a pot with some molten lead already in the pot. Years later, Dad found a Lyman Ingot mold and bought it. Fancy. But really not necessary for those rough first casts of large pieces of scrap lead.
I recommend getting rid of the hand held dipper style casting " pot", because its so dangerous to be handling molten lead in such a container. Buy a standard casting pot- either the solid bottom, or the bottom pour pots. I like the bottom pour ones, because I can run any number of different molds under the spout, and mold one, two or 4 cavity molds at will. If you like using a dipper the top pots are the better buy for you. Buy a thermometer for measuring molten lead. Don't depend on the readings on the pot. Everyone has to learn a Rhythm that works for them when casting balls or bullets. Some molds cool down faster than others.
Like others here, I developed a rhythm that would allow me to cast bullets or balls as fast as I could fill the molds. When I got a mold going well, I got very few rejects. BUT, I went through a steep learning curve to get there.
I recall one of my first evenings, I cast for more than 4 hours, and got less than 25 GOOD bullets out of all that. The mold was not hot enough, and neither was the lead. I kept getting wrinkled balls/bullets. I learned. :surrender: :thumbsup:
