- description
Adjusting hop on a stock HK45 runs through an arm and gear assembly. This kit puts the adjustment into the outer barrel itself and removes that assembly from the equation.
It works with the stock barrel and with a Maple Leaf. Kross’s own testing favoured the ML MR-Hop, because the curved plate in this kit was shaped around the HK45 hop unit window and seats tightly in it.
The thread is 14mm CCW, which is what puts the aftermarket silencer and tracer market within reach of a pistol that otherwise sits outside it. Printed in nylon using MJF.
Specifications
| Specification | Detail |
|---|---|
| Platform | Tokyo Marui HK45 |
| Thread | 14mm CCW |
| Hop | Integrated adjustment — replaces the stock arm and gear assembly |
| Barrel compatibility | Stock or Maple Leaf; best results with the ML MR-Hop |
| In the kit | Replacement outer barrel, hop adjustment grub screws, hop plate, M0.9 Allen key, knurled barrel cap |
| Material | Nylon, MJF printed |
| Manufacturer | Kross Airsoft Design |
Good to know
Kross publish an installation video for this kit, so the fitting sequence is documented rather than something you work out as you go.
Frequently asked questions
Do I need a Maple Leaf barrel? A stock barrel works fine. The MR-Hop is simply where Kross saw their strongest results, thanks to the curved plate included here.
Is the Allen key included? Yes, an M0.9. The Glock version of this kit dropped its key when the grub screw size changed, but the HK45 kit still ships with one.
Does the barrel cap come with it? Yes — a knurled cap is part of the kit.
Will a 14mm CCW tracer fit straight on? That is the thread the kit is built around, so yes.