The AK Operators Union, Local 47-74 has posted a video on the capabilities of operating AK-47 weapon systems in “emergency situations”. In short, they show that the AK weapon system can be operated without the dust cover and more interestingly, without the recoil spring (with some risk that the bolt will come off the rails and hit you).

I would not recommend you fire an AR without the recoil spring. You will damage your receiver and/or extension.