Turn your heat down, start with turning it down 10 then turn it down 20, you will find a good temp for the bottom between them, this will help you on undercutting. Start turning down at about 4 o'clock. When you meet the other side dont just stop and end, try to blend it together then bring it back to you as you stop. It may help you to aim your rod back into the cap also. Hope this helps, it's alot easier to show someone.
man big kahunna's way is the same way i do it,,,but know this,,,its not the only way,,everybodys different. rod angle is really important when working with 70+. im assuming this is the rod your using because you said bell hole and bottom in the same sentence. now then,,on 6 inch,,hes right you shouldnt have to turn your heat down on a cap from top to bottom. on 6 inch you should be able to step across the bottom instead of hanging out and puddling or horseshoeing or however you do it. just try to take longer steps across the bottom giving it time to cool and step right back in it with more metal,,,if you have the right heat youll be amazed at how quick it will cool. another important key like kahunna said,,,when you drag out of the bottom peel it back towards you,,if you step out in the direction your going,,most likely your button will be low,,bring it back to you and see how that works,,but keep in mind, the quality of all passes before the cap,, determine the appearance of the cap. for example,,,if you rat rail your filler,,,your gonna rat tail your cap or have a hard time getting slag out. try to keep the your filler flat. what i do is just take longer steps across the bottom of 6 inch and move a little faster on the filler,,it flattens it out nice for me,,but its different for everybody, try it out and if you got some more problems,,,we'll get you fixed up