AMX 13 challenge

These are some great builds! I’ve always been attracted to the AMX13 style turret. But one thing I can’t find online…is how does the gun recoil get absorbed. My understanding is that the gun is hard mounted to the turret, so what moves to absorb the force? Does the top portion of the turret move a little bit? Anybody ever see a video of one firing? I’d be very grateful if somebody in the know can explain this…