The ATI GSG FireFly is a .22 LR semi-automatic pistol with a 4.9-inch threaded barrel and a 13+1 capacity. The slide and frame are aluminum with a green finish and serrations on the slide; the grip panels are textured. A Picatinny rail on the frame accepts lights or accessories, and the sights are adjustable. 
 

Key Specifications 

• Brand: ATI 
• Model: GSG FireFly 
• Caliber: .22 LR 
• Action: Semi Auto 
• Capacity: 13+1 
• Barrel Length: 4.9 in (threaded) 
• Color/Finish: OD Green 
   

Detailed Features 

• 4.9-inch threaded barrel for suppressor or muzzle device attachment 
• Green aluminum serrated slide and green aluminum frame construction 
• Textured grip panels for positive handling 
• Picatinny rail on the frame for accessories 
• Adjustable sights

The ATI GSG FireFly draws consistent praise for the threaded barrel on a rimfire pistol at this price. Owners use it as a suppressor host, and the green aluminum construction feels solid compared to all-polymer alternatives in the same tier. The 13-round capacity is generous for a .22 pistol.

The aluminum slide and frame combination is a real differentiator. Trigger feedback is adequate for a rimfire pistol, though it is not the primary draw. The adjustable sights and Picatinny rail round out a package that is easy to accessorize without extra expense.

The common criticism is .22 LR reliability with certain ammunition types. Like most rimfire pistols, the GSG FireFly prefers high-velocity loads and can be finicky with bulk standard-velocity ammo until broken in. Accuracy at close range is solid, and most owners are satisfied once they find the ammo it runs best.