Sig Mosquito -- First Impressions

I just bought a Sig Mosquito despite the dire warnings from some about reliability issues. After approximately 350 rounds, I have had exactly two failures to feed properly, one failure to eject (stovepipe), and one failure to fire. For my purposes, strictly target practice, that is well within acceptable limits.

Before I ever fired the pistol, I read the owners manual, the maintenance manual and the Sig website faq's, and I tried to follow all the advice to the letter. I carefully cleaned the grease off, and oiled the pistol and magazine. I have only used CCI Mini-Mags (36 grain, 1260 fps) as Sig recommended. I added a drop of oil to the port on the slide after every 100 rounds. After each use, I thoroughly clean it.

Both of the failure to feed issues arose after I had added oil on the slide through the port. I wonder if I might have gummed things up by adding the oil. I looked at the round that did not fire, and there was an impression from the firing pin that looked normal, so it could have been a bad round. In any event, so far I am really pleased with the reliability of this pistol.

My main reason for purchasing this pistol is the cost of ammo. Obviously the .22 is a lot cheaper than my usual .40 caliber. Since the recoil is much lighter I also find that I become less fatigued shooting the .22. I am not the greatest shot, but I am able to hit 8 inch targets reliably at 50 feet, and my patterns are getting smaller with practice. I think the Sig is likely more accurate than I am.

I carry a Glock 23 .40 S&W. I originally became interested in the Mosquito because it is approximately the same size. Now that I have it, I actually find it more comfortable to hold than the Glock. It just seems to fit my medium-large sized hand really well. There may be a larger caliber Sig in my future.

Stay safe!

I have a Sig P226 9mm and find the Mosquito fits quite nicely with it when it comes to range time.

I've been through several of the 'other' 22's and agree that the Mosquito deserves better press than many have given it. I too found that if you follow Sig's instructions it not only works but works well. My last outing at the range consisted of 300 rounds of Remington Golden Bullets with absolutely ZERO malfunctions in slow and fast fire. I've also found that time spent with the Mosquito has caused my accuracy with the P226 to go up considerably. My groupings have probably been cut in half as a result. Plus the Mosquito has a very high cool factor since its a scaled down version of the full size with all controls included and where they should be.

I neglected to mention in my original post that I also changed out the spring. The manufacturer now recommends using the light duty spring (the longer one) with any ammo less than 1400 fps. I agree about the coolness factor. I am hoping that my marksmanship will continue to improve, and that any improvements will transfer to the .40 caliber glock as well. That is why I bought the mosquito in the first place. It also happens to be a lot of fun to shoot.

Where would you get this light duty spring?

The Mosquito comes from the factory with two springs. The heavy duty spring is installed, but you just swap springs when you field strip it for the initial cleaning. This is one gun you have to clean before you shoot it, and it really likes to be kept clean.

I just bought one yesterday and pick it up on Thursday. I can't wait, if for nothing else but to be able to shoot all day without going broke. The one I got was the multi-cam and looks really great and seems built good as well. I will post after I get it to see if I have any problems like I have been reading but I intend to stick with the CCI mini-mags at least for the first 2000 or so.This will be my first .22 and hope it will make me a better shot with the rest of my arsenal.

Glad to hear it, keep us posted on how she works out. The CCI's work great but be sure to also try the 525 box of Remington Golden Bullets, these are high velocity also and mine runs excellent with them, and at a considerable cost reduction.

For what it's worth, today I borrowed my son's Mosquito—new out of the box. I had no malfunctions in ~150 rounds with CCI Mini Mags and Stingers. The gun is very comfortable and fun to shoot. The sights are terrific!

I just traded for a used Sig mosquito from a guy who broke it in correctly, replaced the springs, and had some work done on the trigger. This gun is about 2 years old and it is incredible. I just ran 200 rounds of bulk federal ammo and had 1 misfeed. I should say i fired about 40 rounds and my wife shot the rest.

Just as an FYI, I talked with Sig a couple of times over the past few days about the Mosquito and found out the following that I wanted to pass along.

- Original purchaser has a lifetime warranty on a new Mosquito. Sig pays shipping for the first year, after that, owner is responsible for shipping costs.
- The slide has been reworked over the years and newer models do not appear to encounter cracked slides like earlier models.
- The gun is made for Sig by GSG of Germany.
- Recoil springs should be changed every 2000 rounds.

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Originally Posted by dwheeless

- Recoil springs should be changed every 2000 rounds.

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Every 2000 rounds seems very frequent to me. I have put about 1000 through mine in the past month or so. I will keep this in mind if I start encountering problems, but I do not expect to replace the recoil spring any time soon.

BTW: After approximately 800 rounds of CCI MiniMags exclusively, I tried a small box of the Remington Golden bullets. I think I had 1 misfeed in 50. I am getting 1-2 per 100 of the CCI, so that seems about the same performance, and the Remingtons are a little cheaper. The muzzle velocity is about the same for either brand, which I suspect is the issue some people have had.

From the Box:

CCi Standard Velocity: 1070 FPS 40 Grain (0032)
CCi Mini Mag: 1260 FPS 36 Grain (0031)
Remington Gold: 1280 FPS 36 Grain

Remington Gold And the Mini Mags are both high velocity Ammo.

My Mosquito loves the Mini Mags and Golds and win super x but wont do any standard velocity ammo with the spring that it came with in the gun (High Velocity Spring).

I'm curious to see if it would fire regular velocity if i changed the spring.

My Mosquito Broken down:

400 Mini Mags: no issues
40 Winchester super x: no issues
10 Federal Bulk High Velocity: no issues
30 CCi Standard Velocity: 1 SP, 3 FTE, 1 FTL

Haven t put any gold through it yet but i have a gut feeling it will perform flawlessly.

I tried both springs with standard velocity ammo and didn't get one successful feed with either one. However, both springs seem to work equally well in mine with Remington Golden Bullets and CCI Mini Mags. I can't really tell a difference between the springs so in using high velocity ammo, I couldn't be more pleased with the gun's performance

I decided to try to save some money, so I bought a box of Winchester ammo. 525 rounds for about $21.00. I figured since the muzzle velocity was 1280 fps, it would work about as well as the Mini-Mags. I was wrong. I had multiple failures to feed, eject, fire, etc. I even had the slide jam a couple of times. I could not go more than a few rounds without a failure. I gave up completely after 100 rounds. The gun was absolutely filthy when I was done, and I had cleaned it after the previous use. No more Winchester for me.

I picked up my Sig P22 last Monday. Beautiful gun! It was cleaned througly before shooting. I have put about 150 rounds through it and had a few problems but nothing to get in a snit about. This P22 seems to really like CCI stingers, and the CCI minimags are great, however, it wont for a minute tolerate the cheaper ammo. The cheaper ammo is where i seem to have all my problems, FTC, 1 FTFire. After about 500 quality rounds have been fired through it i will evaluate the need for a lighter spring (it came with one) and the possable need for polishing. I plan to take it to the range today and let er rip, but only after the honey do's are completed. I have worked over 100 hours straight in the last 5 days and have been forced to neglect the manly duties around the house. HAPPY WIFE, HAPPY LIFE.

It is now broken in and with the stiff spring it shoots every thing except the federals. i really really like this gun.

Until I started using the CCI Mini Mags, I had feeding problems with all but one of the magazines.

No feeding or misfires since, but the slide does not lock back after the last round fired.

Does anyone else have this problem?

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Originally Posted by bemobo

Until I started using the CCI Mini Mags, I had feeding problems with all but one of the magazines.

No feeding or misfires since, but the slide does not lock back after the last round fired.

Does anyone else have this problem?

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Have u rried using the lighter spring?

I went back to the CCI Mini Mags (after a horrible experience with the Winchester) and I am happy again. I had one failure to feed in 100 rounds. Not sure what's up with that. I am using the lighter spring with the CCI ammo. I can buy the Mini Mags for under $7.00 per hundred at Walmart, so I don't have much need to screw around with cheaper alternatives. I am close to 2000 rounds through this pistol, and I am very pleased with it. My marksmanship has definitely improved, though I'm not sure how much of this has transferred to my .40 caliber Glock.

hyfly1:

You figured it out! I was a Mosquito owner and as long I kept it well oiled and fed it CCI Mini Mags, I never had an issue. I had good luck with Federal Auto Match ammo too. It was about $15 for 325 rounds - a little less expensive than CCI.

Like you, my main reason for getting the Mosquito is because it was of a similar size to my Glock. So I got it for inexpensive range practice.

Good luck!

My last trip to the range I fired 100 rounds of the CCI with no failures whatsoever. Maybe the gun is getting broken in. I will give the Federal Auto Match a try if I happen to see it. Thanks for the tip.

I recently picked up a bi-tone mosquito. I tried running the cheap round lead nose ammo and it was so dirty, and under powered it wouldn't fire a whole magazine with out issues. I oiled, cleaned, swapped springs, nothing seemed to work. Then I got online and starting to read about the ammo issues. I picked up a box of the Remington Golden bullets, and it's been running flawless ever since. So far I got about 150 rounds though it, and it's a very nice shooter.