So, in the original post a month ago, the o-ring that caused the mayhem on the pellet domes and not allow the probe to seat completely was caught between the liner and the brass insert: 
Those of you purchasing the new Wildcat make sure to look for all, in my case 3, o-rings if and when you remove the liner. These are around the liner and my guess is they are spaced evenly along the length.
something was poking the dome??
the rubber nub came out of the pellet probe when I took her apart and I later come to find this nub is a friction piece at the back end of the shroud on the inside edge, how it got into the probe is anyone's guess.
No kidding the pellet would not chamber fully, so look carefully folks.