Hello all. Just got an unfired Chinese Mak 90 ( AK clone ) in and I'd appeciate some info / opinions. I've heard this debate go both ways. Does the rear of the bolt carrier make contact with the rear of the receiver at the rear trunion while cycling during fire , or does the recoil spring stop this contact just short of it hitting anything? Also, while manually cycling the action, do you think I'm damaging the carrier, bolt or trunion when I pull the carrier back with reasonable force ( nothing abusive ) until it stops ? Just to test feeding, extraction and ejection with a few rounds, I applied manually what I thought to be about the same bolt speed as actual firing to feed and eject the rounds which flew probably 10-12 feet . During this the carrier was pulled back until it made contact. Since it's new and tight yet, this modest amount of force is needed to just get the action to not stay locked back . I know they are built like tanks, but at the same time I sure don't want to hurt or abuse anything. Will normal firing ( if I decide to shoot this 1 ) be as or more violent to parts as manual cycling occasionally would be ? Thanks