The SOCOM Gemtech Oasis out of the box has a high FPS which is too high for many fields. With no GBB, all of the air goes directly to propelling the the BB. Inside the rear locking mechanic, there is a lever holding a ball bearing on top of a spring which in turn holds an aluminum "ride" plate. This spring tension dictates how much air is released per shot. To reduce the amount of air, the quick fix is said to be reducing the height of the ball bearing. This .stl part takes the .235 ball bearing height down to .05 flat surface. The shaft on the end it to keep it centered on top of the spring.

I have only just modeled this part in Fusion360 based on digital caliper measurements and I have not yet attempted to print something so tiny on my Ender 3 V2. In reality I should probably mill this on a lathe out of metal for strength and durability, but for now, the design is in testing phase.

UPD: Printed and tested.

Acceptable at US indoor range:330-350
This gun with stock bearing: 388 f/s

Try as I might, I cannot get this to work. I have uploaded various test versions if anyone else wants to give it a go. Let me know what you find out and perhaps how I need to modify my part. TIA