The RetroArms QSC tool is designed for removing and installing the RetroArms QSC spring guide. It screws into the thread of the spring guide and allows it to be extracted from the gearbox against the spring pressure, without opening the gearbox. It replaces the hex key, providing a much safer grip.

Features

• Anodized aluminum body
• Diamond knurling for maximum grip, even with greasy hands
• Threaded steel insert
• CNC machined
• For RetroArms QSC spring guides
• The QSC (Quick Spring Change) system allows changing the spring from the rear of the gearbox without disassembly; the tool makes the operation quick and safe, reducing the risk of the spring guide being released suddenly

The RetroArms stainless steel spacer corrects the angle of engagement (AOE) between the sector gear and the piston. Installed between the piston head and the piston body, it shifts the piston back so that the first tooth of the sector gear engages the rack at the correct, nearly perpendicular angle.

The right thickness depends on the combination of piston, piston head and gearbox: 2 mm is the most commonly used size, 2.5 mm is for larger corrections and 3 mm for major corrections. A trial fit is recommended before final assembly, along with checking the full piston stroke and the air seal before closing the gearbox.

Benefits

• Removes the load on the first piston tooth, the main cause of its breakage
• Reduces the risk of tooth skipping in high-power or high rate-of-fire setups
• Extends the life of the piston and gears

Features

• Material: stainless steel
• CNC machined
• 3.3 mm countersunk center hole for a flat-head screw
• Reinforced version of the POM AOE shim: does not compress or deform under load
• Compatible with most pistons and piston heads (minor adjustments may be needed)

Specifications

• Thickness: 2.5 mm
• Outer diameter: 17 mm

Technical note: AOE correction should always be combined with a sorbothane damper on the cylinder head, and the air seal (nozzle length and piston stroke) should be rechecked after installation.

The RetroArms thrust bearing mounts in the piston head and allows the spring to rotate freely during compression, reducing wear and torsion.

Features

• Ball thrust bearing

Specifications

• Outer diameter: 15 mm
• Inner diameter: 6.9 mm
• Thickness: 1.5 mm

The Retroarms trigger contact spring is designed for version 2 gearboxes in M4/M16 electric rifles. It ensures correct contact operation when the trigger is pulled.

Features

• Compatible with V2 gearbox (M4/M16 electric rifles)

The Retroarms switch spring is designed for the fire selector of M4 series airsoft replicas. It is a small replacement part, useful for precise selector operation.

Features

• Compatible with the M4 series fire selector

The RetroArms stainless steel spacer corrects the angle of engagement (AOE) between the sector gear and the piston. Installed between the piston head and the piston body, it shifts the piston back so that the first tooth of the sector gear engages the rack at the correct, nearly perpendicular angle.

The right thickness depends on the combination of piston, piston head and gearbox: 2 mm is the most commonly used size, 2.5 mm is for larger corrections and 3 mm for major corrections. A trial fit is recommended before final assembly, along with checking the full piston stroke and the air seal before closing the gearbox.

Benefits

• Removes the load on the first piston tooth, the main cause of its breakage
• Reduces the risk of tooth skipping in high-power or high rate-of-fire setups
• Extends the life of the piston and gears

Features

• Material: stainless steel
• CNC machined
• 3.3 mm countersunk center hole for a flat-head screw
• Reinforced version of the POM AOE shim: does not compress or deform under load
• Compatible with most pistons and piston heads (minor adjustments may be needed)

Specifications

• Thickness: 2 mm
• Outer diameter: 17 mm

Technical note: AOE correction should always be combined with a sorbothane damper on the cylinder head, and the air seal (nozzle length and piston stroke) should be rechecked after installation.

The RetroArms blowback connector plate is CNC-machined from aluminum and is designed exclusively for replicas with the Marui NGRS (Next Generation Recoil Shock) system.

Features

• CNC-machined aluminum construction
• Compatible only with replicas with the Marui NGRS system

The RetroArms Type A bolt catch is CNC-machined from anodized EN AW 7075 duralumin and designed for M4/M16/AR15 series rifles. The light blue color adds a personal touch to your replica. The model is available in several colors.

Features

• Anodized EN AW 7075 duralumin
• CNC-machined
• For M4/M16/AR15 series rifles
• Color: light blue

The RetroArms safety catch spring is designed for version 2 gearboxes in M4/M16 electric rifles. It is useful when replacing a weakened or lost spring.

Features

• Compatible with V2 gearbox (M4/M16 series)

The RetroArms stainless steel spacer corrects the angle of engagement (AOE) between the sector gear and the piston. Installed between the piston head and the piston body, it shifts the piston back so that the first tooth of the sector gear engages the rack at the correct, nearly perpendicular angle.

The right thickness depends on the combination of piston, piston head and gearbox: 2 mm is the most commonly used size, 2.5 mm is for larger corrections and 3 mm for major corrections. A trial fit is recommended before final assembly, along with checking the full piston stroke and the air seal before closing the gearbox.

Benefits

• Removes the load on the first piston tooth, the main cause of its breakage
• Reduces the risk of tooth skipping in high-power or high rate-of-fire setups
• Extends the life of the piston and gears

Features

• Material: stainless steel
• CNC machined
• 3.3 mm countersunk center hole for a flat-head screw
• Reinforced version of the POM AOE shim: does not compress or deform under load
• Compatible with most pistons and piston heads (minor adjustments may be needed)

Specifications

• Thickness: 3 mm
• Outer diameter: 17 mm

Technical note: AOE correction should always be combined with a sorbothane damper on the cylinder head, and the air seal (nozzle length and piston stroke) should be rechecked after installation.

The Retroarms QSC buffer tube mount is CNC-machined from steel and allows the stock tube to be attached to the body. The mounting screws are included.

Features

• CNC-machined steel

Package Contents

• QSC mount
• Mounting screws

The RetroArms gearbox shells made of CNC-machined aluminum are designed for Tokyo Marui SOPMOD M4 NGRS replicas and are ETU compatible. The gearbox shell houses the entire mechanism of the replica, and a strong shell is the foundation of any upgrade.

Features

• CNC-machined aluminum
• For 8 mm bearings/bushings
• ETU compatible

Specifications

• Weight: 116 g

Package Contents

• Gearbox shell
• Screws
• Spring guide
• Bearings/bushings not included

The RetroArms Type B bolt catch is CNC-machined from anodized EN AW 7075 duralumin and designed for M4/M16/AR15 series rifles. The yellow color adds a personal touch to your replica. The model is available in several colors.

Features

• Anodized EN AW 7075 duralumin
• CNC-machined
• For M4/M16/AR15 series rifles
• Color: yellow

The RetroArms V2 gearbox shell is CNC-milled from AW 7075 T651 duralumin, lightweight yet extremely strong (590 MPa), for electric rifles with a version 2 gearbox (M4, M16, AR-15, etc.) to the Tokyo Marui standard.

Replacing internal parts, including the gearbox shell, should be carried out by a qualified technician.

Features

• CNC-milled 7075 T651 duralumin
• For 8 mm bushings/bearings
• Quick spring change system
• Not compatible with the MAXX cylinder head

Specifications

• Weight: 124 g (shells only)

Package Contents

• Gearbox shell
• QSC spring guide
• Screws
• Bushings/bearings not included

The RetroArms Type B bolt catch is CNC-machined from anodized EN AW 7075 duralumin and designed for M4/M16/AR15 series rifles. The black color adds a personal touch to your replica. The model is available in several colors.

Features

• Anodized EN AW 7075 duralumin
• CNC-machined
• For M4/M16/AR15 series rifles
• Color: black

The RetroArms set contains 20 ultra-thin 0.01 mm shims for 3 mm axles. They allow very fine adjustment of the gear position in the gearbox.

Features

• For axles with a diameter of 3 mm

Specifications

• Thickness: 0.01 mm

Package Contents

• 20 shims

The RetroArms type B stainless steel cylinder is designed for setups with a 240–289 mm inner barrel. The cylinder is part of the gearbox compression group and must be chosen according to the inner barrel length.

Features

• Stainless steel
• For 240–289 mm inner barrels

The RetroArms stainless steel plate set mounts in the pistol grip of M4 series rifles and compatible models. It is a useful replacement part when installing the motor and grip.

Features

• Material: stainless steel
• Compatible with M4 series rifles and compatible models

The RetroArms magazine catch is made of metal and is designed for M4/M16 series rifles and compatible models. It is a durable replacement part for the original component.

Features

• Metal construction
• Compatible with the M4/M16 series and compatible models

The RetroArms Type B bolt catch is CNC-machined from anodized EN AW 7075 duralumin and designed for M4/M16/AR15 series rifles. The orange color adds a personal touch to your replica. The model is available in several colors.

Features

• Anodized EN AW 7075 duralumin
• CNC-machined
• For M4/M16/AR15 series rifles
• Color: orange

The RetroArms set contains 10 shims of 0.2 mm for adjusting the axial play of the gears in the gearbox of AEG replicas.

Specifications

• Thickness: 0.2 mm

Package Contents

• 10 shims

The RetroArms type C stainless steel cylinder is designed for setups with a 290–369 mm inner barrel. The cylinder is part of the gearbox compression group and must be chosen according to the inner barrel length.

Features

• Stainless steel
• For 290–369 mm inner barrels

Specifications

• Length: 72 mm
• Weight: 30 g

The RetroArms V2.2 gearbox shell is designed for HK417 replicas. It is CNC-machined from EN AW 7075 T651 aluminum (duralumin) with protective anodizing against corrosion, a material stronger than ordinary steel (590 MPa versus 390 MPa).

Features

• CNC-machined 7075 T651 aluminum, anodized
• For 8 mm bushings/bearings

Specifications

• Weight: 110 g
• Color: black

Package Contents

• Gearbox shell
• Spring guide
• Mounting screws

The RetroArms anti-reversal is CNC-machined from steel and is designed for RetroArms V2 gearboxes. The package includes two springs with different tensions, so you can choose the right option for your setup.

Features

• Steel construction
• CNC machined
• Compatible with RetroArms V2 gearboxes

Package Contents

• 1 anti-reversal
• 2 springs (1 stronger, 1 weaker)

The RetroArms type B sector delay clip, for a 3 mm axle, mounts on the sector gear and slightly delays the tappet plate cycle for proper BB feeding. It is especially useful in high rate of fire builds.

Features

• Polymer construction
• For a 3 mm axle

The RetroArms Type B bolt catch is CNC-machined from anodized EN AW 7075 duralumin and designed for M4/M16/AR15 series rifles. The red color adds a personal touch to your replica. The model is available in several colors.

Features

• Anodized EN AW 7075 duralumin
• CNC-machined
• For M4/M16/AR15 series rifles
• Color: red

The RetroArms stainless steel shim set is designed for gears with 3 mm axles. The shims fix the exact position of the gears in the gearbox; proper shimming ensures correct meshing, lower noise, reduced friction and a longer service life for the gears, bushings and motor.

Features

• Material: stainless steel
• Inner diameter: 3 mm (axle bore)
• Assorted thicknesses
• Compatible with V2/V3 gearboxes and derivatives with 3 mm axles

Package Contents

• 10 shims with 6.2 mm outer diameter and 0.1 mm thickness
• 10 shims with 6.2 mm outer diameter and 0.2 mm thickness
• 5 shims with 8 mm outer diameter and 0.1 mm thickness
• 5 shims with 8 mm outer diameter and 0.2 mm thickness

The RetroArms type D stainless steel cylinder is designed for setups with a 370–650 mm inner barrel. The cylinder is part of the gearbox compression group and must be chosen according to the inner barrel length.

Features

• Stainless steel
• For 370–650 mm inner barrels

The RetroArms V3 gearbox shell is CNC-milled from AW 7075 T651 duralumin, lightweight yet extremely strong (590 MPa), for electric rifles with a version 3 gearbox (AK, etc.) to the Tokyo Marui standard.

Replacing internal parts, including the gearbox shell, should be carried out by a qualified technician.

Features

• CNC-milled 7075 T651 duralumin
• For 8 mm bushings/bearings
• Quick spring change system
• Not compatible with the MAXX cylinder head

Specifications

• Weight: 105 g (shells only)

Package Contents

• Gearbox shell
• QSC spring guide
• Screws
• Bushings/bearings not included

The RetroArms anti-reversal is CNC-machined from steel and is designed for RetroArms V3 gearboxes. The package includes two springs with different tensions, so you can choose the right option for your setup.

Features

• Steel construction
• CNC machined
• Compatible with RetroArms V3 gearboxes

Package Contents

• 1 anti-reversal
• 2 springs (1 stronger, 1 weaker)

The RetroArms type B sector delay clip, for a 4 mm axle, mounts on the sector gear and slightly delays the tappet plate cycle for proper BB feeding. It is especially useful in high rate of fire builds.

Features

• Polymer construction
• For a 4 mm axle

The RetroArms V2 gearbox shells are CNC-machined from steel and feature an integrated quick spring change (QSC) system. The gearbox shell houses the entire mechanism of the replica, and a strong shell is the foundation of any upgrade.

Features

• CNC-machined steel
• For 8 mm bearings/bushings
• Integrated QSC system

Specifications

• Weight: 363 g

Package Contents

• Gearbox shell
• Screws
• Spring guide
• Bearings/bushings not included

The RetroArms anti-reversal spring is a small but essential part that keeps the anti-reversal latch in contact with the gear. It is useful when servicing the gearbox or replacing a worn-out spring.

Features

• Spring for anti-reversal latch

The RetroArms cut-off lever is CNC machined and designed for version 2 gearboxes. The cut-off lever controls semi-automatic operation by cutting the power after each shot.

Features

• CNC machined
• Compatible with V2 gearboxes

The RetroArms gearbox shell is CNC-milled from AW 7075 T651 duralumin, lightweight yet extremely strong (590 MPa), and is designed exclusively for HPA rifles of the M4/M16 series (version 2).

Replacing internal parts, including the gearbox shell, should be carried out by a qualified technician.

Features

• CNC-milled 7075 T651 duralumin
• Quick spring change system
• For HPA M4/M16 (V2) rifles only
• Not compatible with the MAXX cylinder head

Specifications

• Weight: 135 g

Package Contents

• Gearbox shell
• QSC spring guide
• Screws

The Retroarms screw set is designed for mounting the M4 3K-Carbon outer barrel from the same manufacturer. It includes both fixing screws and barrel centering pins, for precise assembly without play.

Features

• Compatible with the Retroarms M4 3K-Carbon barrel
• Includes barrel centering pins

Package Contents

• 2 M3 x 6 mm DIN914 screws
• 2 M3 x 6 mm DIN915 screws
• 3 barrel centering pins

The RetroArms damping centering ring with a 24 mm outer diameter keeps the inner barrel centered in the outer barrel and reduces vibrations. It is especially suitable for precision and/or very long barrels.

Features

• Polymer construction
• Recommended for precision or very long barrels
• Color may vary

Specifications

• Outer diameter: 24 mm

The RetroArms cut-off lever is CNC machined and designed for version 3 gearboxes. The cut-off lever controls semi-automatic operation by cutting the power after each shot.

Features

• CNC machined
• Compatible with V3 gearboxes

The RetroArms gearbox shell is designed for M249 or PKM replicas with a quick spring change system. It is CNC-machined from EN AW 7075 T651 aluminum (duralumin) with protective anodizing against corrosion, a material stronger than ordinary steel (590 MPa versus 390 MPa).

Features

• CNC-machined 7075 T651 aluminum, anodized
• For 8 mm bushings/bearings
• Quick spring change system

Specifications

• Weight: 240 g
• Color: black

Package Contents

• Gearbox shell
• Mounting screws

The RetroArms damping centering ring with a 32 mm outer diameter keeps the inner barrel centered in the outer barrel and reduces vibrations. It is especially suitable for precision and/or very long barrels.

Features

• Polymer construction
• Recommended for precision or very long barrels
• Color may vary

Specifications

• Outer diameter: 32 mm