[Kozzie]

I ran into that situation with my type 56-2. I installed a Prometheus bearing spring guide and a Prometheus 110 spring. The Prometheus spring is longer than the stock spring, same for the guide. It was like you're describing, the piston didn't have enough room for the last tooth to clear and be released. The motor would halt when the piston ran out of travel and the gearbox locked-up. I was able to replace the Prometheus guide with a Madbull bearing guide (which is shorter) and all is hunky dory.

edit: The RS high torque motor that comes in the type 56 should have no problems with that spring. The gearbox used by the type 56 is smaller than a Marui V3. You either need to gain space from somewhere else or find a smaller spring.