Airsoft Masterpiece LimCat Perfect Sight Standard Kit with Optic Front Sight - Black Rifle The recoil spring is nice

The recoil spring is nice and strong which helps to create a very nice blowback feel

Angry Gun Super Recoil Kit  Stainless Steel construction  ROF Adjustable  Design for upgrade your Original Recoil Kit  Able to Increase the Recoil force  Suitable for WE M4 Series Airsoft Gas Blow Back GBB Rifle

SKU GP-AEG038-BK Item Weight (gram) 3135 Major Color Black Length 700mm / 780mm (Extended) Barrel Length ~260mm Hop-up Adjustable Shooting Mode Semi/Fully Automatic Gearbox Type 2 AEG Motor G&P M120 High Speed Motor AEG Power Source Up to 11

KJ / TANIO KOBA M4A1 Gas Blow Back Rifle (Version 2)

Airsoft Masterpiece LimCat Perfect Sight Standard Kit with Optic Front Sight - Black Rifle The recoil spring is niceProduct Brand: Airsoft Masterpiece Product Code: SK LCPS Weight: 350g Length: 200. 0mm Material: Aluminum