Midcap Syndrome

Midcap syndrome is a term referring to a weapon malfunction characterized by low velocity (10-50 m/s) when using strong push-type magazines like PTS. The spring pushes the BBs into the BB chamber too forcefully and that pressure deflects the nozzle. After firing 10-70% of the magazine's capacity, the performance stabilizes (if the low performance persists throughout the entire magazine, the issue lies elsewhere.)

Prevention involves not buying another magazine but rather repairing inside the gearbox; typically, shortening the spring on the nozzle frame is sufficient to achieve a stronger pressure of the nozzle frame against the cylinder head. Another option is to replace internal parts, especially ensuring a smooth but reasonably tight movement of the nozzle on the cylinder head's nose. The cylinder head must be firmly supported against the gearbox shell (ideally using washers or opting directly for MKII cylinder head from EPeS).
The nozzle must also securely hold onto the feeder arm, not fall off (the nozzle can be glued to the arm, but this solution may not be long-term or suitable).