Originally Posted by
Menace
I'm guessing that delrin was chosen owing to weight/mass, cost, and the fact that, with a roller sear, durability shouldn't be much issue.
After doing some digging I suspect the sear reset issue you are having may be related to the fact that the new plate uses a timing rod hole instead of the original slot.
An old article of Ravi's dealt mentioned a similar situation, with a similar result, owing to the fact that a hole will change the timing vs. a slot.
May not be the same issue in your case, but your experience sounded eerily like his, and it might be interesting to experiment with a modified delrin plate that has been slotted, to see if the problem goes away.