Here’s a set of prints that can turn an Action Army AAP-01 into a M6C SOCOM from Halo. This set includes four 3D printed pieces and the hardware needed to mount it to an AAP-01.
The slide is attached with a single M5x12 bolt and blows back when firing, while the outer barrel/mock suppressor is attached with two M3x12 bolts.
*This set does not come with an AAP-01.
Want to print the pieces yourself? 3D models are available here.