Wait, it's a pneumatic ram...but it uses a spring? On an autococker...there's only one ram...and that's the one on the front block lol. It's been quite a long time since I've teched a cocker, but no ram I've ever come across has a spring in it. Try manually pulling the back block back - if the ram had a spring in it, it would come back towards the gun when you let go (it does do this to some extent but that has nothing to do with the ram. That's the mainspring creating tension the hammer connected to the cocking rod bringing it back).
Check out a Sandridge or an F5 with an LPR mod done to it - same concept.
Or it could be because I'm dead tired and I'm kicking a horse that might not even be....well, alive...
it's all relative lol