Silverback MDRX HPA Conversion Kit

Official HPA conversion kit for the Silverback MDRX AEG. The Silverback MDRX HPA Conversion Kit converts the MDRX AEG platform into an electro-pneumatic HPA rifle. According to Silverback, the system uses a simple and robust open-bolt HPA architecture, designed for reliability, consistent feeding, wide power adjustability and high rate-of-fire capability.

Watch the full review/test video: “Je converti mon MDRX Silverback en HPA / Kit HPA review et Test” — Diaboloman Sniper France.

What is shown in the official photos

• Main HPA assembly with MDRX-specific housing and Silverback branding.
• Pneumatic block with solenoid/electro-valve, black air tubing and push-fit fittings.
• External HPA line with metal quick-disconnect fitting.
• Electronic FCU board marked “SBA MDR-X FCU V1.2”, with Hall sensor, SW1 button, “VALVE” connector and red/black wiring.
• Machined internal components, modular nozzle/cylinder assembly and green/black O-rings for pneumatic sealing.
• Compact internal layout designed to fit inside the MDRX platform.

Practical information from the video

• Installation requires removing the AEG gearbox/system and replacing the firing control board with the HPA FCU.
• The wiring and HPA line must be routed through the rifle; the reviewer notes that the body already has a marked/pre-drilled area for the line exit.
• Reviewer installation estimate: around 1h30 for a first installation while following Silverback’s official video; with practice, around 20–30 minutes.
• Switching back and forth between HPA and AEG is not instant: wiring, the control board and internal routing make it more involved than simply removing pins.
• The HPA hop-up includes a retention modification — a red plastic part — intended to greatly reduce the risk of double feeding, especially at high rates of fire.
• Programming is done with no magazine inserted, with battery and air connected, using the trigger and the semi/full selector.
• Programmable modes mentioned: shooting mode, dwell, rate of fire, DMR cooldown, battery protection, sleep mode, daily/total shot counter and reset/factory reset.

Electronic settings mentioned in the video

• Shooting mode: full auto, burst, binary, semi or safe.
• Dwell: adjusts how long the nozzle/valve cycle delivers air, helping send only the air needed for performance and efficiency. Range mentioned: 2.5 ms to 12 ms; default at maximum, 12 ms.
• Rate of fire: minimum 12 rps, default 20 rps and maximum 50 rps. The video demonstrates 12, 30 and 50 rps; the reviewer considers 30 rps already very high and 50 rps only advisable if magazines can keep up.
• DMR cooldown: delay between semi-auto shots, from 0.5 s to 5 s, useful to limit the firing rhythm for DMR/sniper-style setups.
• Battery protection: default cutoff mentioned at 3.3 V per cell; can be lowered to 3.0 V.
• Sleep mode: standby from 1 h to 10 h, or disabled.

Nozzles and usage range discussed

• The reviewer states that the kit comes by default with the 2-hole nozzle, described as the versatile option.
• 1-hole nozzle: oriented toward low-power setups, roughly 0.5–1 J according to the video.
• 2-hole nozzle: general-purpose range, roughly 1–1.5 J according to the video.
• Full-flow / 6-hole nozzle: aimed at higher-power DMR/sniper configurations.
• According to the video, Silverback recommends working at around 4 to 6.5 bar: below that, cycling issues may occur; above that, excessive air disturbance may reduce accuracy.
• Results depend on barrel length, BB weight, pressure, dwell and hop-up setting. The video stresses that the official measurements are made with no hop-up applied.

Official Silverback performance charts

Approximate values read visually from Silverback’s official charts, with no hop-up applied:

• 1-hole nozzle + 6.05 x 330 mm barrel: from 4 to 10 bar / 58 to 145 PSI, approx. 0.32–0.52 J at 4 bar up to 0.92–1.41 J at 10 bar depending on BB weight from 0.20 g to 0.50 g.
• 2-hole nozzle + 6.05 x 420 mm barrel: from 4 to 10 bar / 58 to 145 PSI, approx. 0.73–1.08 J at 4 bar up to 1.81–2.66 J at 10 bar depending on BB weight from 0.20 g to 0.50 g.
• The charts mark pressure zones: low pressure with risk of unstable operation, ideal pressure, high pressure with possible loss of accuracy, and over-pressure with risk of loss of accuracy or mechanical failure.

Price and availability

Official price and availability are still pending. Silverback confirmed by email that price and release date had not yet been announced by email. The official page/category shows ETA June 2026. In the video, the reviewer says he did not have official pricing at the time of recording and speculates about the complete HPA version; that comment is not an official kit price and should not be used as final pricing.