My Fab Defense KPOS for Glock Review Part Three

'FSSG for the KPOS'
My one and only biggest frustration about the KPOS right now, is making an FSSG work on it. First problem, is that you will need a special FSSG (Fire-Selector Switch for Glock) for it, instead of the usually cheaper, flat, sliding or rotary FSSGs that are more readily available. This is because you need a backplate that will act both as an FSSG, and also as anchor for the removable cocking lever. This means you will have to get the rarer, and more expensive variant of the FSSG.

As for installing the FSSG on the Glock: They replace the backplate, and instead of my usual routine of removing the slide from the frame and replacing the backplate, you needed to replace it while the slide is still attached to frame. This is because the FSSG is bulky, and if you install it on your slide and slide it to your frame, it will snag with some of the frame's protrusions.

The way to install it is to lock back the slide using the slide release, then replace the backplate with the FSSG. This would also mean that you will NOT be able to disassemble the slide from the frame easily, you will have to remove that FSSG first, before you can remove the slide from the frame.

'FSSG Fitting Problem'
I was able to buy an FSSG from Bro Spitfire, and it needed gunsmith fitting. There is a sword-like protrusion on the FSSG that goes forward and backwards, and it controls whether the gun goes full-auto or not. The depth or distance of this protrusion seems to vary per model, and is built oversized so the gunsmith can slowly file away by trial and error the length of that protrusion. So what the gunsmith did was file it down a little, assemble, then test by firing a couple of rounds off.

The second problem was that the Gunsmith didn't turn out to be very familiar with the product, and made a crucial mistake: He got confused on when the FSSG was supposed to go full, or semi-auto. So he put the gun on extended or full auto settings, and then filed it down to semi-auto. The result: The FSSG won't go full auto anymore.


It took a bit of time, but he was able to rebuild the sword-like protrusion again. This time, though, I tried to do the filing myself. I didn't trust him with my weapon after that, and I thought I could do much better. After all, after the problems I went thru with the FSSG, I learned a lot about fitting it, and testing it by dry-fire to see if it goes full auto. The test is actually relatively simple, and let me share it here:
- First, set the FSSG to its full auto, or when the sword-like protrusion is extended.
- Then rack the slide, and pull the trigger.
- Next, while the trigger is still pulled, rack the slide again, and let it slide to battery. IF you hear the Striker move forward, then that means the gun is going full auto.

Since I now know if the FSSG works, I thought it was a simple case of just filing the sword-like protrusion down a little with the help of a metal file, then fit, and then dry-fire test. THEORETICALLY, this is how it is supposed to work:
- Fit the FSSG, then set it at SEMI-AUTO setting, or with the sword-like protrusion retracted;
- Do the above dry-fire test. If the gun goes full-auto, it means it needs filing down.
- Remove, file back a little, then test again. Do cycle until the gun goes semi-auto.

If you do the above step right, then when you set it to full auto, then it should go full-auto. So I set out and did that just that. EXCEPT, that it turns out to be not as easy as it seems, as I seemed to have overfiled the sword-like protrusion again, so when I set the gun to full-auto setting ... it goes semi-auto only.

'Extra FSSG'
Its hard to get angry at the Gunsmith, they were nice people (nevermind if they thought I would make a scene and brought a toughie one time). Besides, he acknowledged the problem, apologized, and rebuilt the sword-like protrusion. And on top of that, he gave me an extra FSSG for free. This one looks like an old one, probably an early prototype. It is made of steel, unlike the one I bought from Boss Spitfire which was made of Aluminum, so it should be more durable.

However, it will also rust, unlike Aluminum. Aside from its looks, there is also two other problems with it:
- First, it goes full auto only based on my dry-fire test, regardless of what setting I put it;
- Second, it doesn't have a removable protrusion along its left side that I could use to cock the Glock when it is inside the KPOS.

Theoretically, I could still fire the KPOS with it, as long as I lock the slide of the Glock before I put it on the KPOS, and then just load a live magazine, release the slide lock, and fire away. However, if a misfire or stovepipe occurs, I have no way of racking the slide back.

A better idea would be to install a removable, screw-in rod on the left side (thankfully there is enough space for that). This I intend to do one of these days, bring it to ANOTHER gunsmith who will be able to do that, and hopefully he will be able to do that well this time. That still won't solve the issue of the FSSG not going on selective fire, but what the heck, I want to rock and roll, even with a gun stuck on full auto only.

'Parting Shots'
This big issue with the FSSG is putting a lot of damper on my enthusiasm for the KPOS. Sure, I still have a nice Carbine for long range shooting, but without the "Happy Switch", its just not the same. Besides, it would be sort of an overkill with that shoulder stock and vertical fore grip, for a Glock that only runs on semi-auto.

It's times like this, when I wonder if I would've been better off with just the Fab Defense clip-in sholder stock, a Fab Defense foregrip, and that Croatian FSSG setup. It wouldn't be as compact as the KPOS, but It would've been cheaper overall, and with a reliable "Happy Switch". In fact, I sort of envy that Croatian FSSG spammer right now. At least he can Rock and Roll and post pics about it.

Perhaps it would've been better if I sold my KPOS and go that route, but I've invested a bit on the KPOS setup already which I can't use on the above set up, like a CAA Short Vertical Grip (the Fab Defense VFG is better for the Glock), low profile laser sight, etc. Anyway, I'm stuck, I hope I can rebuild that other FSSG, and/or improve that metal FSSG. If its too much work and bother, I might probably just drop everything, and go by the Fab Defense Clip-in route.

(End of Series)
Update, 2012-04-19 - Sold off my Fab Defense KPOS in January 2012, no further reviews about it is planned. No regrets, I was able to buy a simpler and cheaper FSSG for my Glock and used it as per what I call a "Machine Pistol Configuration". Look at my other blogs related to that one.

--> My Fab Defense KPOS for Glock Review Part One

--> My Fab Defense KPOS for Glock Review Part Two