the 6 mosfet are the same type and batchIm unclear on this. Are you saying that you have six irfp460 mosfets in parallel or you have three irfp460s in parallel with three other types? If you meant the latter, I really don't recommend that, because the MOSFET with the lowest Rdson will take the bulk of the current. It is best to have all of the mosfets the same part number and from the same production batch (I.e. Buy them all at the same place at the same time) and match parameters of them. Most important parameter is turn on/ turn off time, followed by Rdson. If you have one MOSFET that turns on slightly before the others or turns off slightly after the others, then if brief periods of time, it will be carrying the full load current, which is not good. It is also important to note, that even with perfectly matched mosfets, once you solder them into the circuit, they may have drastically different turn on/ turn off times due to parasitic inductance in your pcb. This is where Good circuit layout comes into play. Make gate traces all as short as possible and all the same length. Also note that more mosfets is not always better. If you look at the numbers, you may get the idea that it would be best to just throw 20 mosfets into the circuit, but remember that the more mosfets you use, it gets exponentially harder to make them share the load and you have to start derating them by higher and higher factors. The manufacturers recommend that if you are going to parallel more than 4 discreet mosfets, that you start looking into MOSFET modules (expensive)
before i will test again i will try to make the gate wires all same length as possible as i can
well i get 6 mosfets because one can hold 20A continuous and the start amp is 100 A : 100/20 =5 mosfets the 6th is for safety