It will depend on the mold you have and the lead you are using. If you are using scrap lead and aren't sure if it soft or hard, simply see if you can scratch it with your fingernail. So for most molds with pure soft lead you should be able to set the pot to 6 and be fine. Some molds you may need to bump it up to 7 or even 8 but just start with 6 and go from there.