Big Bang Self Indexing FM SMG 4.5mm BB

Big Bang Full Metal CO2 Powered Semi Auto 4.5mm Mini SMG Air Gun

Big Bang proudly presents the Self Indexing FM SMG, a heavyweight, full metal CO₂ powered BB carbine that authentically replicates the iconic look and feel of a classic submachine gun in a compact, blowback operated airgun format. This semi automatic replica delivers realistic handling, a reciprocating charging handle, and satisfying blowback action with every shot making it an incredibly fun and immersive choice for close range plinking, backyard target practice, training drills, or simply enjoying rapid semi auto BB firepower.

The Big Bang Self Indexing FM SMG comes loaded with realistic and functional features:

• Heavyweight full metal construction for authentic weight and rugged durability
• Blowback action with reciprocating charging handle for lifelike cycling feedback
• Semi-automatic firing fires one round per trigger pull with fast follow-up capability
• Folding metal stock for compact storage and stable shoulder-fired shooting
• Functional grip safety and adjustable iron sights for practical control
• Picatinny rail under the forearm for mounting lights, lasers, grips, or accessories
• 25-round high capacity magazine for extended shooting sessions without frequent reloads

Powered by standard 12g CO₂ cartridges, this mini SMG propels 4.5mm steel BBs at approximately 360 fps, delivering crisp impact, realistic sound, and excellent range for a BB gun while remaining safe and suitable for backyard or indoor use. The result is a robust, eye catching, and highly detailed CO₂ BB replica that feels and operates like a real submachine gun in miniature.

• Action: CO₂-powered blowback, semi-automatic
• Calibers: 4.5mm (.177) steel BBs
• Power: ~360 fps
• Power Source: 12g CO₂ cartridge (housed in grip/magazine area)
• Shot Count: Approx. 40–60 shots per CO₂ cartridge (varies by temperature and firing rate)
• Magazine: 25-round high capacity BB magazine (self-indexing)
• Barrel: Smoothbore (replica style)
• Stock: Folding metal stock
• Sights: Adjustable iron sights
• Safety: Functional grip safety
• Features: Full metal construction, reciprocating charging handle, folding stock, Picatinny rail under forearm, realistic blowback action, semi auto fire mode
• Overall Length: Approx. 500–650 mm (stock folded/extended)
• Weight: Approx. 1.5–1.8 kg (heavyweight feel)