Here is the MC6 suggested firing schedule (with a slow cooling if you want to use it).
Deg F/hour Temp & hold
Ramp 1 100 220/0
R 2 350 2000/0
R 3 150 2190/15 or where cone 6 is bent correctly, depends on your kiln
mine bends at 2185
To continue with slow cooling cycle
R 4 -500 1900/0
R 5 -125 1400/0
"For bisque firings we recommend slow firing (100C, 180F per hour from 100C to 900C, 212F to 1650F). This is when chemically combined water and organics are burn off. This is especially important with iron bearing bodies to stop any reduction of iron which can over flux clay." " For bisque firing a 5-10 minute soak at the end of the firing cycle can be advantageous......." MC6 John Hesselberth & Ron Roy.
My glaze firing with at Skutt 1027 pretty full is about 8 1/2 hours and bisque about 12 1/2.