This is a replacement priming block for the XYL KM9 Unicorn. This will replace the stock part completely. In terms of purchased parts, this will need 2x: 623 POM Bearings, and 2x: M3x8mm bolts. I have linked the POM Bearings below. Use the bolts to secure the bearings in the slots provided, then close up your blaster. It is meant to work with a longer barrel, one that is 16mm OD the whole way through. The barrels that this blaster comes with: Stock and extended are machined down, and do not make contact with the bearings.
This priming block will not make contact with the stock barrels. I have also noticed that my stock Priming bar screws were too long and were also contacting my barrel. Take a look at these when you print this, they may need to be changed out to M3 SHCS: I used 6mm
Please note that the scratches on my barrel in the photos are from when I tried to use the 16mm barrel with the stock priming block and stock brass rollers.
Bearings: https://www.amazon.com/dp/B08H4J8CG3?psc=1&ref=ppx_yo2ov_dt_b_product_details
The author marked this model as their own original creation.