The file 'Nerf Retaliator/Recon (Retalicon) Spring Rest 3D Printer Model' is (stl) file type, size is 43.5KB.
Retalicon Spring Rest and Spring guide, print at 100% infill for best durability.
You should have enough support to use a high Kg spring, I have tested mine using a 7.5Kg OMW spring and it works flawlessly, potentially up to 9Kg.
NOTE: Your length might be slightly too long, however you can easily sand it down a bit.
retcon_springrest_v4.stl | 222.7KB |