The spring is a key component of the gearbox as its strength—combined with air seal quality—determines the gun's overall performance. Low-quality springs may offer higher-than-rated output at first, but quickly lose tension, shorten, or even break—especially when stored compressed or used with pre-cocking systems. The ULTIMATE upgrade spring from ASG is engineered for maximum consistency and durability. Manufactured from high-quality SiCr spring steel (silicon-chrome), it meets military specs and withstands wear, even under high rates of fire. The progressive winding design starts softer and builds up, reducing stress on the gearbox and motor. Both ends are closed and ground for stability and a secure fit. Each spring is factory pre-tensioned to minimize initial power drop. The black zinc coating protects against corrosion without affecting performance.
Installation
When installing a progressive spring, the tighter-wound end (with denser coils) goes onto the spring guide. The colored-marked end by ASG ULTIMATEgoes into the piston.
ULTIMATE Spring Ratings and Dimensions Table
Model
Stiffness (N/mm)
Color Code
Outer Diameter (OD)
Inner Diameter (ID)
Length (mm)
M95
0.447
Blue
14 mm
11 mm
176 mm
M105
0.467
Green
14 mm
11 mm
189 mm
M115
0.519
Yellow
14 mm
11 mm
188 mm
M125
0.826
Orange
14 mm
11 mm
168 mm
M135
0.943
Red
14 mm
11 mm
178 mm
Key Features
Military-grade SiCr spring steel – high strength and durability.
Masking fabric adhesive tape from Wosport. The tape is made of non-woven fabric and uses natural latex, which leaves no glue after peeling. You can use it for example to stick or protect your airsoft equipment and to camouflage your weapon. Available in several colours.
WoSporT MOLLE TIGER pouch for long SMG magazines in Coyote is a compact pouch designed for H&K MP5 / MP7 magazines with 30 / 40 rounds (and airsoft replicas). It can also be used for AR-9 magazines (SSR9, ARP 9, GP STRIBOG, etc.). Adjustable retention system secures the magazine securely in place. The rear MOLLE webbing allows attachment to a plate carrier or belt.
Silent Industries CNC hop-up chamber ALPHA M4 Gen2 (V2) represents the top tier among upgrade chambers for demanding players who want maximum accuracy and performance. Thanks to the TDC adjustment, clamping ring system, adjustable magazine inlet, and Gen2 improvements, it pushes your rifle performance to a completely new level.