Description
Army Custom 5.1/4.3 Hi-Capa Series Part – Blowback Unit (R501-A-040)
This is an Army Armament (Army Custom) replacement blowback unit for its 5.1 and 4.3 Hi-Capa series pistols, part number R501-A-040. Army Armament is known for affordable, well-built gas blowback pistols, especially its Hi-Capa models, and supplies original spare parts so owners can keep their pistols running.
The blowback unit is the part in the slide that receives the gas from the magazine and drives the slide back on each shot. It takes a lot of work, so its seals and housing can wear over time, which shows up as weak or inconsistent blowback, gas leaks or poor cycling. An original replacement is the simplest fix.
Why replace it
If your Army Hi-Capa has started to cycle sluggishly, leak gas from the slide or fail to lock back, a worn blowback unit or nozzle is a common cause. Replacing the unit restores the gas seal and the pistol’s recoil, and a spare is handy to keep if you shoot your pistol a lot.
Please check the product images to see exactly which parts are included, as blowback units are sometimes supplied with or without the nozzle and internal valve.
Fitting
Empty the magazine of gas and BBs, field-strip the pistol and remove the slide. The blowback unit is held in the rear of the slide; note how the old unit sits before removing it, and fit the new one in the same orientation. Reassemble carefully and test the action before refitting a gassed magazine. If you are not comfortable stripping a gas pistol, a local airsoft technician can fit it quickly.
Key features
- Original Army Armament part
- Part number R501-A-040
- For 5.1 and 4.3 Hi-Capa series pistols
- Restores blowback and gas seal
- Handy spare for regular shooters
Compatibility
Listed for Army Armament (Army Custom) Hi-Capa series pistols as named. Hi-Capa pistols from different makers can look very alike, but parts are not always interchangeable between brands or even between models, so please check your pistol’s model and compare the product images with your original part before ordering. If you are unsure, contact us with your pistol details and we will help.
Care and maintenance
Keep your pistol clean and free of grit, especially after outdoor games, and wipe the outside with a lightly oiled cloth. Put a drop of silicone oil on the magazine seals and valves from time to time, and store magazines with a small amount of gas in them to keep the seals in good condition.
A drop of silicone oil on the blowback unit seals and the nozzle helps them stay supple and seal well.
Who is it for?
For owners of Army Armament 5.1 and 4.3 Hi-Capa pistols who need to replace a worn blowback unit, and for technicians maintaining these pistols.
Please note: This is a single spare part; the pistol is not included. Always empty the magazine of gas and BBs before working on a gas pistol.
