Version 2.5 of the hop-up alignment system, specifically designed for SR25 DMR HPA replicas (Designated Marksman Rifle) using a V2.5 long gearbox.
It combines the PolarStar JACK engine (compact high-power HPA engine, ideal for DMR configurations with extended nozzle travel) and the PROWIN chamber (precision hop-up chamber designed for sniper-style rifle builds).
This kit ensures perfect nozzle alignment in the V2.5 long gearbox, compatible with ICS lowers, eliminating lateral deviations that affect long-range precision in DMR builds. The V2.5 design is adapted for the longer nozzle travel and the specific geometry of the SR25 gearbox.
Compatibility
| Component | Compatibility |
|---|---|
| HPA Engine | PolarStar JACK |
| Hop-up Chamber | PROWIN |
| Base Replica | SR25 DMR |
| Gearbox | V2.5 long (SR25) |
| Lower | ICS or universal |
What the kit includes
- Reinforced rear clip for mounting via rear pin or fixed SR25 stock.
- Extended base with housing for M3 inserts (brass recommended for DMR builds).
- Dual side clip for stable routing of the HPA line in long rifle configurations.
- Front locking top cap adapted for PROWIN chambers and DMR barrels (6.01–6.03 mm).
- Rear plate with hole for an M5 screw (critical fixation for DMR precision).
Required components (not included)
- 6× M3 × 4.2 mm inserts (extra reinforcement for DMR builds)
- 6× M3 × 10 SHCS screws (longer for V2.5 gearbox)
- 1× M5 × 12 screw + washer (rear plate fixation)
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