In response to your pm man and for others to possibly benefit from
It is the hammer and its pronounced ridge on it.
Hammer bump/ drag.
It is what is causing the hang up in the rear when you cock it at times
And is slowing down the carrier assembly both going backwards and forwards when firing.
The hammer is cocked into place by the mating surface plane under the carrier.
If you dig back in my post history on this forum several yrs ago .
Another member had the same issues with a WASR 10.
Another century arms imported 922r compliant gun they sell.
Century gets various styles of hammers/ trigger mechanisms and uses them willy nilly with vastly different hsmmer bump profiles.
They will assemble x amount of guns with what ever .
Then use next sourced parts on another run until out.
It is basically a tolerance stacking issue from not using matched parts in the century arms system.
Your hammer bump profile is extremely high and sharp.
The rest of the trigger assembly is a single hook design which century installed.
Most m70 series have a double hook design
The " hooks" are what keep the hammer withheld in the cocked position on each of the wings of the hammer.
Their are dozens of vids on the web you can google to fix the problem from a simple gentle contouring of that pronounced edge bump and a polishing of trigger components.
Another issue century has is hard hammers versus bolt tail and carrier tail peening due to components not being same sourced and heat treated/ harden properly for each other.
Another option is a after market replacement trigger or just a replacement hammer with a rounded over profile hammer .
But you can google fu this stuff and address the problem if you are comfortable doing the work yourself and get that wpn running correct.
That tutorial is in this forum with pics.
I think it was Antelope Sniper that had the same problem you have.
