I bought a GSG Firefly online (I won with a really low bid) at Gunbroker. Basically I got the gun including shipping, fees, everything sub $200. Initially I was excited because it seemed like a great pistol. Apparently the GSG Firefly is the same company and factory in Germany that made all the Sig Mosquito pistols.

Little did I know after diving in online that the Mosquito is a notoriously ammo picky gun. My GSG straight out of the box was let's say 'so so'. I had failure to feed, failure to extract, failure to eject, and problem after problem. I was getting kind of frustrated with it to be honest. I ended up taking the gun apart and doing some simple things that I thought would help.

Among one of the problems I had was my slide, if you pulled it back slowly and released it slowly it would stick in place. No slide lock, just stuck. A gentle tap and it would go into battery but it would bind a little.

Fix 1

I got a soft buffer wheel and some red rouge and I polished everything in the inside of the bottom of the slide that was making contact. I even buffed the hammer a little bit just to make sure. While I was at it I slightly polished the feed ramp and guide rod.

Still no go. Grrr. It helped substantially but the gun was not reliable. Every mag would have a problem.

Fix 2

I got in some good light and slowly cycled the gun (with snap caps) and I saw what I thought could be a problem. The bullets in the magazine were held up at such a steep angle it was interfering with other functions of the pistol. What I did is disassemble the mag(s) and see what if anything I could figure out.

What I noticed was the spring in the magazine the bottom of it is flat, but the top of it is angled to mimic the angle of the follower. I took that spring out and turned it over so that the angle was opposite of the follower. The 'tip' of the spring was now putting pressure on the back of the follower instead of on the front of it.

When I reloaded that mag and compared it to how they came out of the factory, the factory ones, when loaded the bullets were about 25 or 30 degrees from horizontal. After my mag spring flip, the bullets sat about 15 to 20 degrees from horizontal. I don't know exactly how many degrees different they were, but the difference was visually noticeable.

VIOLA! The fix was in!

I ran 4 or more different kinds of ammo, including a box and a half of CCI subsonic suppressor ammo, 45 grain winchester subsonics, and the dreaded federal blue boxes that it has been absolutely hating. I shot a couple other brands too, and I did it all suppressed. I went through about 300 or so rounds--all suppressed with almost no (or very limited) problems. About the only time I had any real problems is when the gun started to get caked up with carbon on the face of the slide. It got so thick in fact that the slide couldn't shut properly. I wiped it off, ran a bore snake through the barrel once, and continued to fire.

I think I have the problem fixed. Around 300+ rounds suppressed, including about 80 rounds of CCI subsonic, about 80 rounds of Winchester 45 grain subsonics, a lot Federal blue box (which has been my nemesis here) and some others and very few problems. I was just literally doing mag dumps.

It did not run flawless, but I eliminated around 90%+ of the problems. I would attribute some of the stoppages that I had to trying to push the gun to the limit and see just how dirty it would run.

I will do more testing but that gives me hope. I will run a bunch non suppressed tomorrow and see if there is any stoppages once carbon build up isn't a thing.

Other stuff

I bought extra mags for the gun so now I have 4 extra mags... and all of them came out of the package as I described above. I reversed the spring in all of the mags and ran a variety of ammo with each one and generally it ran like a top.

I put this up here for two main reasons--- to get feedback from you guys... and also just in case anyone else is frustrated with their gun too they might find this.

Please comment and give thoughts on this.