Sig Mosquito


May 9, 2013, 09:50 PM
I would really like one of these, but I have heard some bad reviews. What have been you experiences with this gun?

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May 9, 2013, 10:01 PM
One of my shooting buddies has one. It is a little picky on ammo. If it were me, I would buy the P229 in .22. You can even get a 9mm and .40S&W conversion for it.

May 9, 2013, 11:32 PM
I have 3 friends that have the Sig Mosquito. Here's what I've seen and heard:

1. Friend number one said it was too picky regarding ammo and he sold it because it jammed all the time.

2. Friend number two is a Sig addict and he loves his. He pretty much only shoots CCI mini-mags and it rarely has a problem. He has reported jams with other kinds of cartridges.

3. Friend number three says that mini-mags work well with far less jams than any other brand of shells. When shooting stuff other than mini-mags, it was jamming a LOT until the gun passed about 500 rounds. Now it is reportedly a lot better than when it was new.

Based on those three friends of mine, I bought a Ruger SR22. I've only fired about 400 rounds through it, but so far it has eaten every single kind of cartridge I've put in it. Remington std. vel. targets, cci mini-mags, surplus military std. vel. LR - they're Remingtons, Federal bulk pack and Winchester bulk pack. The only failures were failures to fire and they were the Winchester. About 10% of them were failing to fire in ANY pistol I tried them in - 4 different kinds of pistols. I sent them back to Winchester to their lab to look at. The SR22 is far from a target pistol, but it wasn't meant to be one anyway. It's a fun pistol to plink with and mine has been very, very reliable. I have a custom Buck Mark and it's pretty boring to shoot because it's heavy, it's very accurate and the trigger is wonderful... it all adds up to boring for a .22. There's no recoil so it's almost like you're not shooting. :) The Ruger is lighter, less accurate, but fun to plink with.

If you want accuracy, spend some more $$ and get a nice Browning Buck Mark or one of the old-style Rugers, etc. Personally, I love the ergonomics of the Sig Mosquito the best of all of them, but I didn't buy one based on reviews from friends and what I've read.

May 9, 2013, 11:58 PM
The balance for a blowback .22 pistol is a delicate one. The slide and recoil spring need to be just the right weight and spring strength.

The good news is that it's possible to tune them over enough of a range to get them to work well with a range of ammo.

I too have heard that the Mosquito generally likes Mini Mags. But those are noticably more powerful then regular rimfire standard or high velocity rounds.

I had a problem gun. It was odd because when I got it I was regularly buying CCI SV ammo with the 40 gn bullet and it worked just fine. I then switched to 38gn HV CCI Blazer and the problems started. Couldn't make it through a mag without at least two jams.

The clue was that I noticed that the SV casings ejected out with far more energy than the HV Blazer. After pondering this for a while I realized that on a direct blowback gun like this that the HV round was both faster and lighter. So the time in the barrel was enough less that the actual total impulse reflected back through the casing to the slide was too low a value to send the slide back with enough energy to clear the spent casing correctly before picking up the new round.

So despite the apparent higher velocity and energy of the HV round I went to a softer recoil spring that I had to make. But this did the trick. It now works very reliably with both HV and SV ammo of a number of types.

However I DO avoid ammo with bullets that have a relatively square'ish nose shape. Those still give my semi .22's issues more often than not.

Now the issue will be to find a softer spring. Or you can try clipping up to perhaps two coils from the stock spring. This actually makes the spring more stiff for the remaining length. But it'll reduce the amount of preload and if you only need a little adjustment it can work just as well as a new softer spring.

But before you leap into a Mosquito you'll want to shop around and make sure you can find a source for softer springs if you're not resourceful enough to make them yourself.

May 10, 2013, 12:37 AM
I have a new Mosquito. They now come with 2 different recoil springs so you can tailor the spring to the ammo. Mine has been perfect with CCI Standard Velocity, and CCI Blazers. I have over 600 rounds through it. Perfect. I also have a Ruger SR22P. It however, has not been perfect. It is ammo sensitive. It will load, fire, eject, then not pick up the next round. It does this with Winchester, and Federal bulk. It runs fine with Blazers. Back to the Mosquito... It has a heavier DA first pull than the SR22P. Its more accurate than the SR22P. It seems very well made. Mine is Desert Digital Camo with the threaded barrel. I like mine enough that it goes shooting with me every time I head to the range.

May 10, 2013, 12:58 AM
I recently bought one. I shot 1/2 of a federal champion buck pack (approx 250-260 rds). I also shot some CCI blazer bulk pack ammo (approx 150 rds) I had NO malfunctions whatsoever. The pistol ran flawless. I did a complete fieldstrip and cleaning before I shot and made sure the rails were greased. I would recommend this pistol to anyone.
As far as the Ruger SR22 goes if you get a good one you will be happy. Unfortunately several that I know about have had to go back to ruger, The last one for a barrel with no rifling. Just go to www. and click on the rimfire section. There are several people that sent theirs back for one reason or another. Ruger to their credit fixes them fast and ships them back usually within a few days. Too bad their quality control is suffering at the moment.

May 10, 2013, 01:22 AM
I know of quite a few people who bought the Mosquito. One is very happy with it, shoots it often and reportedly has had no problems. The rest complain of frequent malfunctions. Actually, it often seems as though I hear about as many complaints from Mosquito owners as I do from all of it's competitors put together. If it were me I think I'd pass on it. As others have mentioned, the Mosquito, with it's fixed barrel, might shoot better than the Ruger SR22, but the SR22 has a far better reputation for overall function.

May 10, 2013, 10:59 AM
I bought one new some years ago because it had a threaded barrel and I thought it would be fun to get a suppressor for it. The ergos are outstanding, especially for Sig owners who want something that feels like their 9mm, 40., .45, etc.

I don't shoot mine much because it's really not all that accurate (accurate enough for plinking and general use) and the trigger is really gritty. I recall that it likes higher velocity rounds but I haven't had problems with mine like some people have written about other than the crappy trigger. The biggest issue is getting another magazine. They're hard to come by and stupidly expensive.

I won't likely sell mine but I wouldn't recommend one either. I like shooting my Buckmark Practical and Kimber 1911 conversion (on my various 1911's) far more.

May 10, 2013, 11:08 AM
I have one that has never had a problem. But use round nosed ammo only, mine prefers CCI, but will eat most every thing else if it has too. Like one guy said, you can change the springs to fit your ammo. Not a real Sig fan myself, this is the only Sig I own and I have quite a few handguns, but I do like my Sig.
When I go to the range, and have rimfire ammo, I will take the SIg, a Single Six and a Ruger Mk III. I seem to always enjoy shooting the Sig the most.

loose noose
May 10, 2013, 11:41 AM
I was in the market for a newer .22 pistol, I presently have a single six, a MKI, a Berreta Mini, NAA etc. I was looking for a Ruger MKIII 22/45, but to no avail. I tried a Mosquito at a local gunstore but had problems grouping the rounds and found it to be rather inaccurate. Next I tried a Browning BuckMark for about the same price, needless to say I loved it, and bought it immediately, very accurate and reliable.:D

May 11, 2013, 12:17 AM
My wife has one and we have fed it a steady diet of CCI mini mags since it was born, close to 2,000 rounds now. First 500 rounds, a few FTE, but things are good to go now. She likes to be kept clean and lightly oiled. She's silver over black and sports a Crimson Trace laser. It's my wifes little baby and she loves it.

May 11, 2013, 06:06 PM
Thanks for all the input guys. I'll will consider before purchasing my next handgun. I REALLY like the way the Sig Mosquito looks and feels. However I want something that will be pretty reliable. Thanks again for your input.

Armed 24/7
May 12, 2013, 12:45 AM
I have had one for 5 or 6 years. I put the lighter weight "white" spring in it. It runs 100% with CCI mini mags. That is what the manual reccomends. It runs pretty well with Federal auto match bulk. It chokes on just about everything else.

May 12, 2013, 03:57 AM
Been eying a Sig p229 classic 22lr. Anybody have any input in its reliability?

May 12, 2013, 03:34 PM
My Mosquito was seriously picky about ammo, the trigger was disappointing, and accuracy was so so. I traded it on a Sig Trailside ( and it is a great deal better pistol. They can be found at very reasonable prices for what you are getting.

May 12, 2013, 08:36 PM
I would really like one of these, but I have heard some bad reviews. What have been you experiences with this gun?
I have shot them quite a bit (between myself and buddies we must have just about one of every .22lr handgun). That said, we found that ONLY if we broke them in with about 200 rounds of the HOT stuff (at the time all we could find was Aguila HV which gives CCI a run for their money) would they then "reliably" cycle 'junk' bulk SV ammo. Literally if we failed to break it in as described, they ran only on HV ammo.

I opted for a GSG/SIG 1911-22 only because I was looking for something that allowed for 1911 platform practice (I must say, it was not nearly as finicky about ammo as was the Mosquito).

May 12, 2013, 08:56 PM
I reluctantly bought a used 2012' model a few months back after reading mixed reviews. Turns out, most of the bad reviews are on older models. Seems like Sig made some improvements in recent times. Mine is 100% reliable as long as I feed it the recommended CCI mini mags. It's mostly a single shot jam-o-matic with most other lower ammo so far. ( They say they get more ammo brand/powder tolerant after a 1500 rounds or so. Mine is maybe 1/2 way there). All that said, I love it. It feels just right in the hand, has bright sights and a very decent SA trigger. ( Better than the Ruger and Walther I tried in the same price range anyway.) Accuracy is much better than I expected for one of this style and price range. The extra spring and different height front sights are a nice option too. Bottom line, I would buy another . (

May 12, 2013, 10:42 PM
I shot mine again yesterday, It shot perfectly. I was shooting some Federal Bulk, and wasnt thinking about if it would run correctly or not. I was just sitting here reading the above posts about how ammo sensitive the Mosquito is, and realized I have shot Blazers, Federal Bulk, CCI SV, Wolf Match, and Eley. It has fired every round loaded into it perfectly. Mine is new, and I have read the new ones are much better than the older versions, as far as reliability. I like mine alot, and would buy another.

May 12, 2013, 11:32 PM
I bought one despite the reviews. I polished the feed ramp with my dremel and smoothed out the small lip at the top of the feed ramp. Ran 300 rounds of Federal bulk through it without a hiccup. I did have a FTE after but the gun was dirty. All in all a good gun.

May 13, 2013, 12:37 PM
I worked on one last year that wasn't reliable. Taking it apart, I found way too many small parts and it was difficult to detail disassemble/reassemble. After altering the extractor, it was much more reliable. I wouldn't buy one.

May 13, 2013, 06:30 PM
I have a new Mosquito (3.9”, 10 rnd) and they come with 2 different recoil springs so you can choose between low velocity or high velocity ammunition. Mine has been perfect with CCI MINI-MAG 40gr CPRN which is recommended and you receive a $10 rebate. I also have a Colt Gold Cup (5”, 12 rnd) and I have found that pistol to be superior to the Mosquito. It has a better trigger and is more accurate than the Mosquito. Before I purchased my Mosquito I used my friends Desert Digital Camo with the threaded barrel (4.9”).

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