Sig Sauer Mosquito - A New Shooter's Review

dirtd0g

New member
I figure as a new shooter with absolutely no major background in firearms (outside of Boy Scout plinking decades ago), I will review my most recent purchases on this forum. Maybe I can help newer shooters with their decisions and even you old, salty dogs at the same time. If I find a thread reviewing the same piece I am, I will consider responding to that if it won't derail the discussion.

The benefit to being a new shooter and never really having participated in shooting culture is that I haven't learned any bad habits and I haven't been interested in the activity long enough to become "brand-blinded" or force-fed "haterade" against certain makes, models, or calibers. I am a clean slate; if I like it I like it.

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No... I'm not THIS new.

As a new shooter, please feel free to contribute some constructive criticism and correct any mistakes I make with terminology. Gun anatomy is very new to me, but something I find positively intriguing and would like to "get right".

I went out gun shopping for the first time since receiving my Massachusetts LTC a couple of weeks ago. My wife got hers as well and our adult daughter got her FID. We have been shooting a few times a month for awhile with a close friend who is the vice president of a local range and getting a good feel for what we like, what we want to have in the house, and honing our skills.

We decided our first purchases will be .22 LR "plinkers". I wanted to own a decent rifle and a decent pistol right off the bat. We can keep practicing both shooting and maintaining our firearms in a fun and economical way. When we end up purchasing larger caliber pieces, we'll still take these to the range.

I walked into a shop the other day looking for a decent, older Ruger 10/22 as I prefer rifles to handguns. I wanted a nice, old, wooden-stock and something that was manufactured early enough to have a 25rd magazine for those days where I didn't feel like being frugal. They had a solid assortment of .22 LR "plinkers" but the 10/22 they had was way too "tacticool" for my tastes. The AR15 style .22s looked like a lot of fun but just too pricey for what I wanted. I did consider the Henry AR7 but even that was more than I wanted to spend for a first family purchase.

Shooterselement_10-22_mag3.jpg

Who would want to stick lasers and rails on something this pretty?

On my way out I passed the pistol case and saw a Sig Sauer Mosquito. I had researched all manner of .22 LR pistols and knew of the scores of complaints and horror stories about the piece. But, at just over $200, I was considering it. I did some more research, called a few friends, and despite the mixed reviews and "love-it-or-hate-it" responses, decided to go for it.

As many of you may know the Sig Sauer Mosquito had a rough introduction into the market. Stories of endless jams, failure-to-feeds (FTFs), failure-to-ejects (FTEs), and other cycling problems filled the internet. People polished chamber and feed-ramps, recommended expensive and hard-to-find high-velocity ammunition, and even decided the gun is best used as a "malfunction trainer". However, the people that love it REALLY love it and claim to have no problems whatsoever.

I took the plunge.

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Simple, handsome, and feels like quality...

I figured it would be better to have a $200 lemon than a $300 lemon and, at the very least, I may be forced to learn about the mechanical intricacies and engineering behind similar semi-automatic handguns. I had a silver-linings before I knew how cloudy the situation was; preparing myself for disappointment.

During my research I found that the Mosquito should come new with 2 springs. One for standard velocity rounds and a stronger one for higher velocity rounds. It seems as if many "early adopters" didn't read their manual as everyone who stated they installed the standard spring had very few issues cycling issues with the Mosquito. Most reviewers do state that quality high-velocity ammunition works better, but many report having no issues running cheap stuff especially after 300 or 400 rounds of quality rounds.

As soon as I got the gun home I stripped it and inspected it. The thing was absolutely filthy. There was fouling in the chamber on top of what looked like the factory-applied protective coating. The chamber and feed-ramp was coated in a sticky, tar-like residue and the first few cloth strips I pulled through the barrel came out black. I was generous with the CLP and cleaned the ever-loving-shiznit out of the thing. I wiped it down and did it again. After each swab and rag was coming out merely speckled with filth, I lubricated the important points, reassembled the gun, and put a few more drops of CLP in the lubrication port as well as some recommended areas.

Looking at the chamber I can see why some people polish their ramps. The transition from chamber to feed-ramp has a pretty significant lip that I can see flat-nosed rounds catching on. I may polish mine in the future. Disassembly and reassembly is very easy, however it does take a little wiggling to the the slide back on; practice makes perfect!

mosquito_thumb.jpg

May not be worth the risk if everything is working okay already...

The next day I went to an indoor range with 150 assorted cheap rounds including a box of 50x RWS 40gr Target Rifle. I was hoping they would have a few nice, high velocity rounds, but I was stuck with standard stuff.

The pistol performed way above my expectations. It fired off the first 6 full magazines rapidly without an issue; I'm talking Hollywood gangster-style fast. Very smooth action, excellent recoil, and I really enjoy the sightss. I had a FTF halfway through the 7th magazine, cleared it, and went through another 6 magazines without an issue. After over 120 rounds the chamber was looking absolutely nasty which, in retrospect, may have not been helped by my generous CLP application during the initial strip and clean. I had one more FTF, cleared, and ran straight through until my boxes were empty.

I like the trigger although it may be stiff for some people. I have no way to measure it nor do I have the experience to even guesstimate its pull, but it feels pretty good to me. I am able to stay on target and don't feel like I'm straining to make it go "bang".

I am not a good pistol-shooter, and I wasn't trying to zero the sights in on this trip, but I found it to be very accurate. I was able to aim in and hit a 3" group at 25 feet without my prescription glasses and not really caring. All other shots were in a 12" circle between 10 and 20 feet even when pulling the trigger as fast as I could.

After getting it home I stripped it and man it was dirty! But, again, I may have been a bit too liberal with the CLP. It cleans easily enough and I'm sure another trip to the range will shake any excess lubricant out so I don't get that gritty syrup in the chamber.

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Apparently when things look like this, it isn't very good...

I am VERY happy with the purchase and I know it will serve me and mine well until we wear out the barrel.

Much of the negative input I got about the gun was from a friend who worked on a range where they used the Mosquito as rentals and trainers for the public and guests. I wouldn't do this. While I wouldn't call it "finicky" it is obvious that this is a piece that will treat you as well as you treat it. I plan on maintaining all of my firearms and even my cheap "plinkers" are not an exception. While it might be nice and even useful, especially for a range, to own and operate equipment that can keep on ticking after taking a lot of misuse and abuse, I imagine keeping them cleaned and oiled will keep them functioning BETTER.

I do have some higher-velocity stuff coming in soon and will make a trip to the range and try and get another 150 rounds out. Let's see if the extra "oomph" can help the gun cycle thorough the sludge and fouling.

Until then, feel free to respond with your own experiences and let me know if I got anything wrong!

Be safe and have fun!
 
Glad it's working for you...


Most 22lr you can buy is high velocity stuff. I don't see much standard velocity stuff, which is around 1000fps in a rifle.

If the box claims 1100-1200 that is high velocity.

Past that is the hyper velocity stuff over 1400fps.


The problem is that much of the cheap ammo has issues feeding do to its quality not the velocity/power.
 
marine6680 said:
If the box claims 1100-1200 that is high velocity...

The problem is that much of the cheap ammo has issues feeding do to its quality not the velocity/power.

The specifications on the RWS say 1070fps...

So it's really just poor construction that causes the round to get hung up, or what? Bad cases?

There have to be merits to a gun that can eat through everything, though. AND something that doesn't beg to be cleaned after less than 200 rounds. Either way I was told this thing WAS picky, and I didn't find that to be true... However I am finding that it is a "keep-me-clean" gun.

But I'll be sure to update the next time I'm out!
 
Just chamfer the chamber mouth carefully about 1/64 " & enlarge & polish the chamber

Nice post and outstanding pictures. The mouth-breathers and Prevaricators will post claiming THEIR Mosquito runs flawlessly. Others will parrot that you must run the factory recommended CCI ammo, or claim you switch out the springs & etc.

There is no Mosquito which will run Standard ammo reliably without modifications.

You are 95% there. Just chamfer the chamber mouth carefully about 1/64 " and enlarge and polish the chamber so all fired cases extract with a fingernail, and you will have it done. Do those two things and it will never jam.

Polishing all slide surfaces with a dremel tool is useful, also.
 
DonR said:
Nice post and outstanding pictures.

Thanks! My Google-fu was strong today!

donr said:
There is no Mosquito which will run Standard ammo reliably without modifications.

Well, unless my used piece had been broken in well, 148/150 is a 98.7% success rate with standard ammo. Not bad at all and MUCH better than the detractors will lead you to believe.

My review on Cabelas.com I gave it 4/5 stars. It is really good, I like it a lot. It isn't what I would call outstanding perfection. But how often can we call something perfect for real?

I DO plan on polishing the feed ramp and augmenting the chamfer and chamber mouth. However, I'll wait until I have a practiced hand to help me out!

Thanks for the input!
 
Another option you can go if you want to train with 22 and then go up to larger calibers is to get an EAA Witness. You can get them brand new for about 250 shipped in 9mm, 45, 40. You can then convert calibers with a kit. I know the 9mm will go to a 40 and a 22 with a 200+ kit. Might seem pricy, but keeps you on the same platform
 
in the many 22 semi auto firearms I have I just shoot CCI Min Mag. Reliably consistent ammunition. I use the bulk boxed cheaper ammo in the revolvers and bolt actions.
 
veamon said:
Another option you can go if you want to train with 22 and then go up to larger calibers is to get an EAA Witness. You can get them brand new for about 250 shipped in 9mm, 45, 40. You can then convert calibers with a kit. I know the 9mm will go to a 40 and a 22 with a 200+ kit. Might seem pricy, but keeps you on the same platform

I'll have to look into that! However, we don't want TOO many calibers in the house... However, give me a few years and I'll probably end up with something for everything.

peggysue said:
in the many 22 semi auto firearms I have I just shoot CCI Min Mag. Reliably consistent ammunition. I use the bulk boxed cheaper ammo in the revolvers and bolt actions.

CCI MiniMag and other high-quality .22 LR rounds with labeled speeds >1100 are hard to get around here. Stores get it in limited quantities, people buy it all up, then sell it with a 20-50% markup.

I wanted to see how this pistol did with crappy, standard rounds... And it shot well.

I am looking into .22 revolvers and bolt actions, however; Ease of use, ease of maintenance, and the price on some of them is incredible... And, of course, ammo quality matters even less.

Seeing as how fun the range is I would love to have another set to lend out to the old man or my brother.
 
Quality bullets tend to be solid in the case...

Cheap stuff can spin or even wobble a little. That leads to poor feeding in some guns.
 
Mosquito Range Update - Ammunition Test

I ran another 10 magazine through the Mosquito with 3 different ammunition makes.

Of the 30 RWS 40 Grain I had 1x FTF.
At 5 yards 8 rounds did not hit a 3" circle.

Of the 30 American Eagle High Velocity I had 1x FTE and 1x FTF.
At 5 yards 5 rounds did not hit a 3" circle.

Of the 30 CCI Minimag I had absolutely no issues whatsoever.
At 5 yards 1 round did not hit a 3" circle.

I dumped a mixed magazine at the end with no issues.

I'm pretty sure the sights are off. I have to aim 1" or so to the right to hit center. My accuracy issues are probably more to do with my sloppy technique and getting used to the gun than the ammo or the gun at this point.

I was going to do some more intensive accuracy testing but I managed to pick up my first 10/22 with a 30 round magazine and wanted to have some fun with that instead.

And, yes... It is VERY fun.

I'll be going to the range tomorrow and have will see if I can get more input for you guys.
 
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Mosquito Range Update - Accuracy Test

After shooting another 100 rounds I came to two conclusions:

[1] CCI MiniMags and other high-quality .22 LR rounds run like butter through this thing. Even though "standard" velocity and cheap stuff may produce FTFs and/or FTEs or other cycling problems less than 5% of the time, anything >1100 FPS will cycle better, run cleaner, and shoot straighter. MiniMags and (gasp) Remington's "Golden Bullet" were the top contenders on today's shoot. RWS and American Eagle HV had some issues, but nothing that wasn't solved by a quick ejection.


[2] This thing has no issue hitting sub-3" groups at 25' offhand.

After adjusting the sights (yes, it was shooting to the left) and getting some pointers from my instructor I was hitting the circle every shot at 25' without an issue. I was even pinging 12g shotgun shells off the top of the frame after figuring out where to aim the damn thing. The lack of recoil makes follow-up shots hilariously easy. You can dump 10 rounds very quickly and keep each round where you want it to be.

Doing some beginners' defensive shooting drills I found the Mosquito to be more than adequate as a trainer. Because it is 90% the size of its big brother you don't feel like you're training with a toy. It's weight and balance and operation are so similar to a full size semi-auto that running the same drill with a Glock 19 or my wife's S&W M&P 9mm meant the movements and muscle memory transferred over perfectly.

I am getting some Sellier & Bellot 22 LR HVHP 38 grn ammo in tomorrow... Hopefully. I'll report back here with my findings.
 
Dog,
Try some CCI Blazers if you can. Both of my Smiths (2206, 41) love that stuff. It's usually cheaper than the MiniMag as well. Nice write up, btw.
 
Range Update - Final Tests

I got that Sellier & Bellot 38gr HVHP ammo in the other day and dumped a few magazines down range with the wife.

The Mosquito performed flawlessly with it. Also ran some CCI MiniMags and, again, absolutely no issues.

I can see why some people advocate for a .22 as a personal defense weapon. The ability to hit within a 5" group while barely aiming and pulling the trigger as fast as you can has its merits. Well aimed I was able to put my rounds in less than a 3" group at 30ft.

Given this item's price point and performance I see no reason to disregard it. While other .22 semi-autos seems to get more of the spotlight, I have found the Mosquito to be more than I thought I would get.

It is, however, a picky eater out of the box.
 
I picked up my Sig Mosquito used and it shoots great with my can attached, I havent shot it alot with the can off but so far its been pretty reliable. I'm pretty happy with the purchase so far.
 
smee78 said:
I picked up my Sig Mosquito used and it shoots great with my can attached, I havent shot it alot with the can off but so far its been pretty reliable. I'm pretty happy with the purchase so far.

Yeah. She's a sweet little shooter. I'm hoping people consider the Mosquito along with the SR22, P22, and the S&W .22 pistols.
 
We love the mosquito and generally have no issues with it. I use good quality ammo and a dry lube (Frog Lube). The dry lube is kind of like a car wax application, you put it on with a little heat to the metal and buff it off when it drys. For long range sessions I put a little synthetic grease on the rails.
 
Range Update - 1.1.16

So, I've been plinking away with this puppy for awhile now.

I still have had no major issues. While the Mosquito wouldn't be my first choice for a heavy duty defense gun, she will fill that role if needed.

She cycled 100 rounds of Golden Bullets today with 1 light strike and 1 failure to eject.

This is still the gun I grab if someone wants to learn about semi-automatic pistols.
 
OP, great write up and pics. I am pleased to see such a postive report on a gun that probably gets more negative press than it deserves. I have a growing interest to add a 22lr pistol as a companion mate to my Remington Nylon 66 22lr that I have owned for 50 years. I would also be happy to pay for 22s versus 9mm for my HK P30S. I might put that Sig Mosquito on my list to consider.
 
A friend has a mosquito and of all the different brands he used CCI worked with out a single problem. Don't remember which of the CCI it was because not all CCI worked. Remember CCI has mini mag, varmint, standard, 22lr, and 22 lr hp
 
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