I've tried a lot of BCAR and PCARs for the HC Diana and felt it makes only marginal difference when it comes to accuracy at a huge FPS lost. I prefer to have the higher FPS. I'm using the after market barrel that has a reverse thread on front of the barrel, but the cap that comes with is black. I wanted it to be orange, so I decided to make a simple design on Tinkercad.
I printed mine at 0.12mm, 2 walls. Because it's so small, I don't think it matters when it comes to infills.
Happy foam flinging y'all.
HC_Diana_Knurled_Cap.stl | 393.0KB |