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SIG Sauer Mosquito Review

SIG Sauer Mosquito Review

It’s nice to see a semiautomatic that mimics its full-size counterpart. Placing the SIG Sauer Mosquito alongside a P226, it’s about 10 percent smaller, but in my average-size hand, it feels just right. The grip is full—meaning none of the fingers of my shooting hand goes past the magazine floorplate—and the backstrap is curved nicely to fit into the meaty part of my hand.

It’s available in variations to please everyone. For the more conservative, the SIG Sauer Mosquito comes in black, traditional two-tone and reverse two-tone with either the slide or the frame finished in natural stainless. But it’s also available in pink, flat dark earth, purple and green, some of which can be had in threaded versions. All models have an integrated Picatinny rail for lights and lasers.

The polymer frame’s frontstrap has a generous amount of molded-in checkering and combined with the wraparound grip panels offers a good purchase. The trigger guard is squared off yet offers a decent amount of room in its interior whether shooting the gun single or double action. And the front of the guard is serrated, and for those who place a support finger in that location, it incorporates a modest hook to keep your finger from sliding off.

There's a manual safety on the slide, and underneath it is a decocker. The rear sight is adjustable for windage, and although they're not night sights, the yellow dots are highly visible.
The trigger face is a wider, target type and nicely curved. In single action, it broke at eight pounds with a moderate amount of takeup. Breaking at 14 pounds, double action did not win a prize, either.

The magazine release is located in the usual place, and I found it convenient because it protrudes nicely for easy use and is angled for maximum finger pressure. Magazines jump out of the well at the press of this button, regardless of whether or not the mag was loaded with 10 rounds.

Directly above the trigger is the takedown lever, and to its rear is the decocking lever. When the SIG Sauer Mosquito is cocked, pushing downward on this lever drops the hammer to what looks like a modified half-cock position. The gun also has a manual safety at the rear of the slide. It’s ambidextrous, which is nice, but it works backwards from the thumb safety you’d find on, say, a 1911: Pushing it down engages the safety; pushing it up allows the gun to fire. The hammer is rounded off and has serrations for sure cocking.

The squared-off trigger guard offers plenty of room, and the front is serrated to keep your support finger in place. Trzoniec was not a big fan of the DA/SA trigger pull, which was on the heavy side.
In addition to the manual safety and the decocking lever, there’s an additional safety at the bottom of the magazine well. By using the special supplied tool, the gun can be rendered inoperable by preventing the hammer from being cocked. The SIG Sauer Mosquito also features a magazine disconnect safety.

The slide is an aluminum-zinc alloy. It has serrations at the rear for racking the slide and a 5.5-inch sighting radius.

The sights are three dot, with the rear adjustable for windage. It’s a nice, clean sight picture, with enough room in the rear notch to acquire the front sight without much hesitation. All of the dots are bright yellow. They’re not night sights, but they’re highly visible even under subdued lighting.

Trzoniec liked the grip, which was comfortable and hand filling, and the wraparound polymer panel’s molded-in texture made for a secure purchase.
One nice addition to this package is that SIG includes two extra front sight blades of different heights to adjust elevation based on how your ammo shoots. SIG also furnishes two recoil springs with the SIG Sauer Mosquito: one for high velocity and one for sporter or standard velocity rimfire rounds.

The slide is an aluminum-zinc alloy. It has serrations at the rear for racking the slide and a 5.5-inch sighting radius.

Disassembly is simple. First, make sure the SIG Sauer Mosquito is unloaded. Close the slide and rotate the takedown lever 180 degrees forward. Pull back on the slide until it clears the frame and lift. Slowly move the slide forward, making sure you catch the recoil spring guide and spring. The barrel is screwed to the frame. Reassemble in reverse order. The instruction manual has additional pointers.


I tested the SIG Sauer Mosquito while our New England winter was in full dress, so I was forced to move into the indoor range, where my chronograph won’t run. Accuracy results are shown in the accompanying chart. While the Winchester High Velocity averaged 2.25 inches, I also shot a group just over an inch with the same stuff, so I think the gun has great accuracy potential. It’s just a matter of experimenting with ammo.

Toward the end of my accuracy testing, one of the last rounds balked on its way to the chamber. I traced that to some lead or wax buildup on the feed ramp, and once cleared off, the gun perked merrily along again. I also felt handicapped by the heavy trigger, although, like everything else, you learn to work around it.


Other than that, I have to say the SIG Sauer Mosquito is a fine gun, well made and shoots well, and it should be dynamite in the field or plinking on the range with a variety of ammunition.


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