Maxed Out Caliburn 4 (C4) with upgrades pre-selected

Price adjusts based on upgrades selected

With the options on this listing, you’ll be shooting 300+ FPS with red dot sight, and other recommended upgrades.

Another great design by CaptainSlug! Pump-action, mag fed, high performance, rigid platform. Great for beginner nerfers or experienced nerfers alike. Darts & magazines sold separately.

Shown as Black
Shown as Purple
Low (140-150 FPS)
Medium (175-200 FPS)
High (200-250 FPS) (+$10.00)
Super High (250-300FPS) (+$34.00)
FPS ranges are an estimate. Performance may vary.
Knuckle Duster (+$9.00)
Lower Stock Spacer
Custom Magwell Text (+$10.00)
Iron Sights (+$4.00)
Red Dot Sight (+$30.00)
Rail Riser (+$10.00)
BCAR (+$25.00)
Rubber Grip Sleeve (+$10.00)
Aluminum Trigger (+$15.00)
Aluminum Sear (+$20.00)
Aluminum Rambase (+$30.00)
Upgrade Plunger
Adjustable Stock (+$20.00)
Ties with Side Rails (+$5.00)
Colored Flatbars
Plunger Black Acetal (+$21.00)
Plunger White Acetal (+$21.00)
Plunger Aluminum (+$31.00)
RMAX (+$20.00)
Stampede (+$40.00)
Angled Foregrip (+$10.00)
Pyrangle Foregrip (+$10.00)
Modular Vertical Foregrip (+$15.00)
Product total
Options total
Grand total
Please double check your printed part color selection. Colors cannot be changed after checkout.


The Caliburn C4 is a homemade Nerf blaster originally designed by CaptainSlug. Pump action, clip-fed, variable fps. Listing is for an assembled and tested Caliburn C4 blaster. Darts, mags, and accessories sold separately. Color configurator provided by captainslug: Caliburn 4 Color Configurator


  • 1 Fully-assembled & tested C4 blaster
  • Passive Magwell Adapter
  • 1 main power spring
  • Spare screws and hardware for maintenance

Blaster Features:

  • More dry-fire safe than predecessor. Great for beginning nerfers.
  • Quick-access buttplate for easy spring swap to adjust power
  • Compatible with both half and standard (elite) dart types
  • Increased durability & rigidity from the previous versions
  • Compatible with all standard picatinny attachments and Caliburn Lower Stock Spacers
  • All Flat bar construction
  • Tool-free passive talon/nstrike mag adapter
  • Faster spring-swaps
  • Optional air-brake plunger feature
  • Maintains the takedown feature
  • Optional o-ring collet muzzle for fast barrel swaps
  • Supports elastic and extension springs for accessories
  • Higher rigidity mixed-print-orientation grip assembly
  • Still compatible with Tooth-And-Nail and other aftermarket parts



  • Darts NOT included. Darts must be purchased separately.
  • Compatible with standard nerf brand darts, as well as short darts
  • Recommended darts: Worker Gen3 Darts


  • Compatible with most standard picatinny-compatible attachment
  • Compatible with all addons featured on the listing. Not compatible with the threaded rod Caliburn’s adjustable stock

What’s involved in the different power options?

*All FPS ratings are an estimate. Performance may vary.*

LOW | 140-150 FPS
Main power spring: 788
Barrel: 14″ .527

MEDIUM | 175-200 FPS
Main power spring: K25
Barrel: 14″ .527

HIGH | 200-250 FPS
Main power spring: Pro25 Plain
Barrel: 16″ .509

Main power spring: K31 + K25
Barrel: 14″ Brass/Alu Barrel

Special thanks to Captain Slug for licensing his design to us. A portion of sales goes to support Captain Slug.


Additional information

Weight 4 lbs
Dimensions 31 × 4.5 × 1.5 in


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