Common SIG Mosquito Problems and Solutions

The SIG Mosquito is a blowback-operated, semi-automatic pistol with a smaller magazine. The pistol is based on the SIG Sauer P226. It is made using an aluminum-zinc alloy and a polyamide frame. A DA/SA trigger is also included.

However, it is notorious for the many issues it brings with it.

The most common SIG mosquito problems are failure to feed and failure to eject, extractor problems, trigger issues, safety issues and magazine catch issues.

In this article, you will find the fix to these problems. Additionally, you will find what the users currently experience with this product. Read the entire article to find out!

Features & Specifications of SIG Mosquito:

Cartridge.22 Long Rifle
Capacity10 rounds.
Barrel Length3.9/4.9 inches.
Weight24.6 oz.
Length7.2 inches.
Width1.50 inches.
Height5.3 inches.
SafetySlide-mounted manual safety/decocker
SightsAdjustable rear  
Common SIG Mosquito Problems
SIG Mosquito

Common SIG Mosquito Problems and Solutions

The owners deal with many common SIG Mosquito problems. Here are some of the issues and how to solve them.

Quick Overview of the Problems and Solutions

Failure To Feed And Failure To EjectTroubleshoot and ensure lubrication.
Extractor ProblemsTroubleshoot.
Trigger IssuesTroubleshoot.
Safety IssuesSend to SIG.
Magazine Catch IssuesTroubleshoot.


Failure to eject, failure to feed, slide stick halfway open, and reluctance to take a new round are common problems. Bob Marley can’t compete with how jammy this thing is.

It occasionally completely gets stuck open when the magazine is loaded. Users can’t get it to feed and eat any type of ammo. The trigger would stop working entirely. Soot might also be found.

The Fix:

With CCI Stinger ammo, the gun shoots smoother. It simply doesn’t like to give enough “oomph” for it to cycle with standard or subsonic ammunition. Rem Oil is also a thing to keep always.

Keep the gun lubricated. Additionally, a plastic magazine will only cause you problems. Change to metal.

If none of the work, call SIG. Dry firing, which can distort the chamber and prevent the round from fully seating, sometimes causes a “Failure to Fire” problem.

The cartridge is fired by the second hammer strike after the initial strike seats the round. In the case of failures to extract or eject, if the fired case exits the chamber, an ejection issue is “likely” to be the cause.

2. Extractor Issue:

The extractor does not fully move down to the slot that’s designed for it. It will not always pull some specific ammo like the Remington GBs. it is like the extractor drops them before they hit the ejector.

The Fix:

It might only require brief stroking if the springs are really powerful. Stingers and Vipers, which have a high velocity, might occasionally be too warm to cycle smoothly in the skeeter.

Using the lighter spring may not work always, just saying!

3. Trigger Issues:

The trigger is quite soft and requires a long and deep pull to fire the gun. It also becomes difficult to shoot. Before the gun fires, it is virtually necessary to touch the frame. It’s just a terrible design.

The Fix:

Polish the trigger bar and the pack just a little. The trigger bar is stamped and has a noticeable burr.

The frame holds the slide release lever and trigger bar in position. Therefore, the items will desire to fall or fly off when the “pack” is removed from the frame.

4. Safety Issues:

The safety lever fails. The safety lever does nothing in any position. Inserting the clip might automatically close the slide. Sometimes, the de-cocking lever will not send the hammer forward.

The Fix:

The slide closing issue is quite serious and you should send the gun to SIG in this case. Only the firing pin is stopped from shooting a cartridge by the safety lever. For rimfires more so than centerfires, dry firing is terrible.

5. Magazine Catch Issues:

After loading a fresh magazine, you should feel and hear the click of the Magazine Catch locking. However, sometimes as soon as you rack the slide to chamber a round, the magazine would begin to slide out of the mag well.

The Fix:

Insert the magazine and then attempt to remove it by tugging on the base if you can manually lock the slide to the rear. If it doesn’t lock, you either have a faulty magazine release or a defective magazine.

Some users facing this problem found metal shavings in the magazine catch. Upon closer investigation, it was discovered that the locking section had only a very small amount of “flesh” (1/16″-1/8″) to grip and lock the magazine in.

Replacement parts will be the only option in this case. Though SIG discontinued making the parts, German Sport Guns continued to make them under the name FireFly.

User Feedback on SIG Mosquito

The Mosquito is a terrible excuse for a weapon. SIG had completely messed up with this one. The Mosquito is usually a complete lemon from the start.

No matter the ammunition users used or the type of spring used, every 10-round magazine would jam or misfeed 2 to 3 times. Safety is the next thing to fail after jamming every other round.

Most owners have several negative comments and experiences with this specific model. It seems like a cute little gun, so this is disappointing. But the Mosquito produced after the February of 2008, is a dependable weapon.

It reportedly fires every round of the .22 caliber ammunition smoothly. It is reasonably reliable and quite accurate. But you need to use the ammo that the SIG recommends.

Exclusively using the CCI Mini-Mag .22 LR rounds, the increased impulse is fantastic. Except for the tiny, slick, and awkwardly located manual safety, the grip is extremely pleasant, and the controls are simple to grasp and use.

The issue is that it seems quite flimsy. The DA trigger doesn’t work (sloppy and inconsistent). The controls all feel rather “loose,” notably the manual safety.

Everything functions, but it all feels clumsy and uncomfortable. The plastic grips appear flimsy. The pot metal slide exudes no reliability. These are some constant complaints from users.  

Frequently Asked Questions (FAQs)

Who made the SIG Mosquito?

The Mosquito was made by German Sport Guns, aka GSG. They import them now as the GSG Firefly. SIG licensed this company to use its name.

How to shoot smoothly with the SIG Mosquito?

If you use a minimum of 36 grain and 1050 fps ammo, they simply run. After about 200 rounds or so, give them a few drops of oil.

Which ammo is the best for the SIG Mosquito?

CCI Stinger ammo. It’s the most demandable 22LR.


Despite giving it lots of attention, it is just the most unreliable pistol that users have. From everything I have read, the mosquito is likely one of the worst and most unreliable pistols ever produced by SIG.

To suggest you some alternatives, the Ruger MK series or S&W Compact 22 would be great! The “Standard of Excellence” in terms of proper operation is CCI Mini Mags. The majority of the gun issues however are related to ammunition.

Trading for something that “may” happen and preparing for something that “will” happen are very different things. The SIG Mosquito will experience the malfunction. So I suggest you avoid this one.

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