Just an update, got a Gretan firing pin assembly as I couldn't find just the cocking piece anywhere in stock. I swapped the bolt shroud as it was matte on the gun and satin on the Gretan (spring compressor is a handy tool).
Reinstalled the Timney and my problem is cured, I couldn't get it to slam fire with minimal sear engagement and no trigger spring pressure after 100+ hard cycles.
Readjusted a bit, now it's light and safe and back in business.
I suspect the 700 oem cocking piece was slipping over the sear, I could see the sear engagement tab on the Rem was shorter/skinnier then the Gretan without taking any measurements when comparing the 2 side by side.