The American Tactical GSG Firefly is a .22 LR semi-automatic pistol built in a DA/SA configuration with a 4.9-inch threaded barrel. Its alloy frame carries a black serrated aluminum slide, and the design includes an accessory rail for mounting optics or a light. A 1/2x28 thread adapter is included for attaching a muzzle device, and the pistol pairs adjustable rear sights with a decocker for straightforward double-action-first operation. 
 

Key Specifications 

• Brand: American Tactical 
• Model: GSG Firefly 
• Caliber: .22 LR 
• Action: Double Action 
• Barrel Length: 4.9 in 
• Finish: Black 
• Material: Alloy Frame, Aluminum Slide 
   

Detailed Features 

• 4.9-inch threaded barrel with a 1/2x28 thread adapter included for muzzle devices 
• Adjustable rear sight for zeroing, paired with a fixed front sight 
• Decocker safety for DA/SA operation, letting the hammer be lowered safely on a loaded chamber 
• Integrated accessory rail for mounting optics or a light 
• Black polymer grips on an alloy frame with a serrated aluminum slide for a secure hold

Owners of the GSG Firefly and similar .22 LR trainer pistols usually buy them to practice trigger control and sight picture cheaply before moving to a centerfire DA/SA gun with the same manual of arms. The decocker and DA/SA trigger get compared often to full-size service pistols, and most owners say the manual of arms feels familiar if they already shoot a DA/SA centerfire gun.

The threaded barrel is a common draw for owners who want to run a suppressor or muzzle device on a rimfire pistol without paying centerfire ammo prices, though some report needing to experiment with ammo brands to get reliable cycling. The alloy frame keeps the gun light for extended range sessions, and the accessory rail sees regular use for red dots or lights among owners who treat the Firefly as a dedicated range or training gun.

Mine has handled everything I have loaded into it without any problems. It has also been very accurate, which makes it especially enjoyable to shoot. The trouble-free operation is the main thing that separates this one from the similarly named Mosquito in my experience.