A look at the infamous GSG Firefly.
Some of you may be familiar with the GSG Firefly, previously known as the SIG Mosquito - and its poor reputation.
After studying up on it a bit, I decided I'd give one a try, knowing fully its reputation as unreliable and problematic. I like a challenge.
After searching around, I purchased one at Defense Depot for about $200.00 with 1 mag. Defense Depot is an IL-based business, and has competitive prices and quick shipping. As a former IL resident, I like to help IL firearms business survive, given the terrible situations they deal with in IL. I've purchased a couple firearms from them so far, and have been very satisfied.
A bit of history -
When first introduced as the SIG Mosquito, and after the initial excitement wore off, owners became angry that 1 - it wasn't actually made by SIG, 2- it was temperamental and wouldn't function with just any ammo, and 3- SIG didn't always warranty it in the event that the slide broke in two, as some did. Some people initially paid over $400 for it, thinking if it said "SIG" it had to be good. SIG eventually dropped it, and the actual German manufacturer, German Sport Guns, decided to produce it as the less expensive Firefly. It wasn't clear if they had made any changes or improvements to the original design or addressed any of the issues.
First thing I noticed when I looked the Firefly over was the chamfer where the feed ramp meets the chamber. Earlier models didn't have it, and the round would shave off some lead as the bullet was chambering, eventually causing malfunctions. The current magazines are silver steel, unlike some of the SIG magazines that were either black steel or plastic. The hammer is silver, and looks like it may be plated, unlike the previous hammers that were black. The slide seems to have a flatter finish than before, and the "GSG" logo is not highlighted as on some earlier models.
I always field strip, check, and lube any new gun, and the Firefly's takedown lever was extremely difficult to move. The screw that holds it is on the opposite side, and if tightened too much will bind the lever. Turning it out 1/4 turn kept it snug enough and reasonable to move. It did feel like there was threadlocker on it, which earlier versions did not have, apparently. The underside of the slide did have some white grease in some areas, which I removed and lubed with Super Lube synthetic grease, which is fairly thin and works well in cold weather. I lightly lubed the small rails at the back of the receiver and on the slide where they ride. I also lubed the trigger bar area and where the hammer rides on the underside of the slide.
I didn't want to make any significant changes or modifications until I tried firing it as-is. It does come with an additional recoil spring, that may be for using lower velocity ammunition. The spare spring has the same diameter wire, and a couple more coils - but is shorter overall. Not sure if that would make a significant difference or not. Taylor Tactical sells a new spring, which is supposed to be lighter than either of the originals.
I took a quick trip to the range to see just how temperamental it was going to be. GSG recommends 40gr CCI MiniMags (1235 fps) which I had, but I also had CCI AR Tactical (1200 fps) and CCI Standard Velocity (1070) and some Norma TAC22 (?). Knowing the slide can break, I wouldn't shoot any hyper velocity ammo. I typically shoot the lowest velocity ammo that will cycle consistently in my .22LR pistols, as most aren't exactly robust.
I wasn't able to spend too much time with it, but starting with the MiniMags, I fired 10 rounds, all of which chambered and fired. I then tried 10 of the AR Tactical, and all chambered and fired. Round #3 of the 10 CCI SV rounds failed to chamber, but ejected the spent case and cocked the hammer. The rest chambered and fired. The Norma TAC22 immediately had issues, not ejecting or cocking the hammer. My S&W M&P22 Compact won't shoot it either, so it's not just the GSG. TAC22 has done well in my bolt rifles, though. The trigger is not great, but it's a plinker, so I don't plan to try to improve it. Not many of the polymer pistols or plinkers are going to have decent triggers, so I just adapt. There are videos out there on how to modify the trigger to make it better.
Overall, with the pistol, 1 extra mag, shipping/insurance, and FFL fees, I have right about $250 in it.
So far - so good. It doesn't appear to be as problematic as some have said. Many people expected the Mosquito/Firefly to be turn-key, which many were not. Others expected it to be able to use any ammo, which many wouldn't. If you don't mind doing some tinkering and possibly some simple mods, it may be a decent, inexpensive, choice for a full-size .22LR plinker.
Just don't expect too much.
I'll add a few photos shortly, and will try a few small mods, the different spring, more functional testing, and some basic accuracy testing.
![Image]()
The slide is not as gray as it appears in the photo, but has a very dull black finish.
Installed spring at the top, spare spring below -
![Image]()
If you need more technical information on the Firefly, search for posts by Mississippi Dave. He's long-gone, but he posted a lot of good info on troubleshooting.
Some of you may be familiar with the GSG Firefly, previously known as the SIG Mosquito - and its poor reputation.
After studying up on it a bit, I decided I'd give one a try, knowing fully its reputation as unreliable and problematic. I like a challenge.
After searching around, I purchased one at Defense Depot for about $200.00 with 1 mag. Defense Depot is an IL-based business, and has competitive prices and quick shipping. As a former IL resident, I like to help IL firearms business survive, given the terrible situations they deal with in IL. I've purchased a couple firearms from them so far, and have been very satisfied.
A bit of history -
When first introduced as the SIG Mosquito, and after the initial excitement wore off, owners became angry that 1 - it wasn't actually made by SIG, 2- it was temperamental and wouldn't function with just any ammo, and 3- SIG didn't always warranty it in the event that the slide broke in two, as some did. Some people initially paid over $400 for it, thinking if it said "SIG" it had to be good. SIG eventually dropped it, and the actual German manufacturer, German Sport Guns, decided to produce it as the less expensive Firefly. It wasn't clear if they had made any changes or improvements to the original design or addressed any of the issues.
First thing I noticed when I looked the Firefly over was the chamfer where the feed ramp meets the chamber. Earlier models didn't have it, and the round would shave off some lead as the bullet was chambering, eventually causing malfunctions. The current magazines are silver steel, unlike some of the SIG magazines that were either black steel or plastic. The hammer is silver, and looks like it may be plated, unlike the previous hammers that were black. The slide seems to have a flatter finish than before, and the "GSG" logo is not highlighted as on some earlier models.
I always field strip, check, and lube any new gun, and the Firefly's takedown lever was extremely difficult to move. The screw that holds it is on the opposite side, and if tightened too much will bind the lever. Turning it out 1/4 turn kept it snug enough and reasonable to move. It did feel like there was threadlocker on it, which earlier versions did not have, apparently. The underside of the slide did have some white grease in some areas, which I removed and lubed with Super Lube synthetic grease, which is fairly thin and works well in cold weather. I lightly lubed the small rails at the back of the receiver and on the slide where they ride. I also lubed the trigger bar area and where the hammer rides on the underside of the slide.
I didn't want to make any significant changes or modifications until I tried firing it as-is. It does come with an additional recoil spring, that may be for using lower velocity ammunition. The spare spring has the same diameter wire, and a couple more coils - but is shorter overall. Not sure if that would make a significant difference or not. Taylor Tactical sells a new spring, which is supposed to be lighter than either of the originals.
I took a quick trip to the range to see just how temperamental it was going to be. GSG recommends 40gr CCI MiniMags (1235 fps) which I had, but I also had CCI AR Tactical (1200 fps) and CCI Standard Velocity (1070) and some Norma TAC22 (?). Knowing the slide can break, I wouldn't shoot any hyper velocity ammo. I typically shoot the lowest velocity ammo that will cycle consistently in my .22LR pistols, as most aren't exactly robust.
I wasn't able to spend too much time with it, but starting with the MiniMags, I fired 10 rounds, all of which chambered and fired. I then tried 10 of the AR Tactical, and all chambered and fired. Round #3 of the 10 CCI SV rounds failed to chamber, but ejected the spent case and cocked the hammer. The rest chambered and fired. The Norma TAC22 immediately had issues, not ejecting or cocking the hammer. My S&W M&P22 Compact won't shoot it either, so it's not just the GSG. TAC22 has done well in my bolt rifles, though. The trigger is not great, but it's a plinker, so I don't plan to try to improve it. Not many of the polymer pistols or plinkers are going to have decent triggers, so I just adapt. There are videos out there on how to modify the trigger to make it better.
Overall, with the pistol, 1 extra mag, shipping/insurance, and FFL fees, I have right about $250 in it.
So far - so good. It doesn't appear to be as problematic as some have said. Many people expected the Mosquito/Firefly to be turn-key, which many were not. Others expected it to be able to use any ammo, which many wouldn't. If you don't mind doing some tinkering and possibly some simple mods, it may be a decent, inexpensive, choice for a full-size .22LR plinker.
Just don't expect too much.
I'll add a few photos shortly, and will try a few small mods, the different spring, more functional testing, and some basic accuracy testing.
The slide is not as gray as it appears in the photo, but has a very dull black finish.
Installed spring at the top, spare spring below -
If you need more technical information on the Firefly, search for posts by Mississippi Dave. He's long-gone, but he posted a lot of good info on troubleshooting.
