I got my Master Pot not too long ago and made a video in another thread about it. This thread is information about what issues and mods I have found and made.
Once I got the Master Pot set up and began casting I realized at once that the factory mould rest had to go. As it is I feel its completely unsuitable, maybe its made the way it is for the Master Caster.
I made a rough mould rest from some 1/8" flat steel scrap drilled a 5/8 hole in it for drips and bolted in onto the existing shelve in the existing holes so no mods to the factory shelve. The mould rest has 3/8 square bar stock welded to it to form a channel for my Lyman and Lee 4 and 6 cavity moulds. I made it slightly loose so as not to bind the moulds. I replaced the shelve nuts with wing nuts and adjusted the new shelve for my Lyman moulds which are a bit higher then the Lee. I began casting with a 4 cavity Lyman 225 gr RN classic bullet for the .45 ACP I had most of the bullets coming out shiny and wrinkled at the 700F setting. The Lee 6 cavity 125 gr RN 9mm bullets were the same . I had heated the moulds very well and did not have lead thermometer so I ordered one. While waiting for it to come in I turned the heat up to the max 800F setting, still wrinkled bullets.
Then I adjusted the thermostat It takes a small flat screwdriver to remove the dial handle as there's a spring behind it then the end of the thermostats hollow shaft has a tiny watchmakers size screw that you turn left counter clockwise to raise the heat hotter. After several test casts letting the pot come to temp for 1 hr 20 minutes I finally started getting good bullets from the .45 mould but still too many wrinkled bullets from the 9mm mould to suit me.
When my Thermometer came I had 840 F with the temp dial at 800 F . I had plenty of heat, so I decided to raise the 9mm Lee mould rest 1/4 of an inch as I feel there may be some turbulence from the longer distance of the spout to the mould then the Lyman which is a taller mould . No overabundance of air flow over the lead stream or air blowing upon it BTW. I do have a large fan that pulls air outside the open garage window which is about 28 inches from the lead stream. I checked with a candle and smoke and the outside air stream does pull a bit but not much. The results are much better bullets from the Lee mould and the Lyman when I get the pot to 775 F on the thermometer
The Master Pot holds 40 pounds of lead alloy allowing extended casting without adding lead to the pot and the spout control is very positive and adjustable with only a slight number of small drips now and then .
I made the Lee insert to slip in and out without any bolts so I can place it when casting with the Lyman then change to the Lee if need be without handling screws on the sides of the pot . I still have to drill a 5/8 lead drip hole in the new Lee insert . the 3/8 bar stock mould guide has about 1/8 of an inch left to help guide the Lee mould which is enough for me. With the Lyman mould its a full 3/8 inch