Misterkey Grenade Launcher – CO2 Blaster

(1 customer review)

CO2 M203 Styled Grenade launcher with improved Spring Thunder level performance


Not to be used in flywheel blasters
Gen3 Red Worker Darts
Mega (red whistle) darts
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Valve Repair Tool (+$10.00)
Valve replacement O-ring (+$1.00)
Red Dot Sight (+$25.00)
2-Point Sling (+$10.00)
Stock (Black) (+$10.00)
Safety Glasses (Clear) (+$2.50)
Safety Glasses (Tacticool) (+$2.50)
Extra Sling point (+$8.00)
Stock (Match Primary Color) (+$15.00)
Stock (Match Secondary Color) (+$15.00)
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LEAD TIME: Blaster Will Ship 4-8 Weeks After Placing Order.


An all-new budget CO2 powered grenade launcher/masterkey shotgun – the perfect blend of power and affordability. Inspired by the M203, this blaster is compatible with Spring Thunder shells and can be used as a standalone pistol grip and stock or mounted on picatinny rails. You can even attach it to itself for double the fun.

This blaster is powered by 12g CO2 bulbs to get around 50-70 Spring thunder level shots per charge. Thus delivering the power of a Spring Thunder in a more portable and cost-effective package. This is a bit of a departure from previous designs, so keep this in mind when maintaining the co2 parts on the unit. Get yours today and experience the power and fun of this new blaster madness.


Frequently Asked Questions

What kind of darts can this shoot?

Anything that fits within the Spring Thunder shell system, so that includes Rival balls, Mega Darts, Regular Darts, Half length darts, Boomco darts

Can it shoot Mega XL darts?

Currently no, though the blaster was initially designed to load in a larger “Grenade” shell, that is capable of fitting in a Mega XL dart. We will likely bring this shell type back. When it does, it should be pretty simple to convert this blaster version to accept those as it only requires the extractor to be repositioned as well as installing the Grenade shell screw on chamber.



*** Updates ***

(February 21st, 2023)

  • New easy pin takedown available for swapping out CO2 cartridges vastly improves quality of life. Reduces tools needed to switch CO2 as well as huge time reduction.
  • Pistol grip is now a proper attachment that mounts onto the Misterkey instead of being permanently attached.
  • Some aesthetic and ergonomic improvements.
  • New Colors and options added

Additional information

Weight 3 lbs
Dimensions 14 × 12 × 7 in

1 review for Misterkey Grenade Launcher – CO2 Blaster

  1. Daniel hall (verified owner)

    Absolute blast of a blaster, already fired off two co2 capsules worth of shots and its just out of the box. The design is KISS and I love it, surprised it took this long for someone to do it. Build quality of the blaster is amazing and looks like it should last a very long time. Can’t wait to have some fun with it in the near future.

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