Progressive AEG and SVD spring M130

Spring is the base of the airsoft gun. It is part which notably affecting shooting range.  This spring is made of tempered SiCr alloy steel wire. Material primary dedicated for machine springs under rhytmic load. Our spring was tested under real airsoft fire and after 10000 shots without lenght or output change.  Progressive (nonlinear) winding gives lower resist at the first phase of pressing, but spring keep the same power.  Material  Tempered SiCr Alloy Steel Wire  Application  For all gearboxes.Suitable also for Guarder pistons.  Tune-up  Power increase 40-45%  Weight  16g Suitable for SVD sniper rifles