I am a FFL/SOT.  I am thinking about a post sample FS2000 and/or PS90.  What is the registered part, the receiver on either or can I Form 2 the trigger pack by itself?  I see them on GB for sale as trigger packs, but was hoping for some insight from this forum.  Thanks.

I was curious about that too, after seeing the registered pack on GB. I have a F2000 Tactical. The "receiver" on that version is the aluminum optics rail. On a Standard model (with factory optic) it was the left barrel support side plate, with embedded s/n plate. Interestingly, both parts are/were sold as individual replacement parts.

MGW lists stocks as F2000/FS2000 but they have different markings.
Their part F482010040 includes the F2000 3-position selector and is marked F2000.

I don't know if there is anything to keep a factory select-fire hammer group (pack) from fitting in a FS2000 stock (like the 2 nubs in a Steyr AUG SA stock), as I don't have a FS2000 to try mine in.
http://www.midwestgunworks.com/page/mgwi/ctgy/fn-fs2000-hammer-group

If it fits, I say just register it. If it doesn't fit, either modify it to fit and register it, or modify the stock and register the stock. Then use a factory hammer group.
Seems logical to me anyway. That's how I plan to Form 2 my AUG, with a registered stock.

I'm curious to know if the "receivers" have any differences whatsoever.


A factory P90 will have a registered receiver marked P90. I don't know if their packs fit a PS90 stock. I suspect not, as MGW has a restriction notice for the P90 stock.
http://www.midwestgunworks.com/page/mgwi/ctgy/fn-ps90-stock-assembly

Here are the differences:

F2000 factory auto


Stop milled off to fit FS2000 stock


P90 factory auto


Notches cut to bypass blocks in PS90 stock




I still don't know if the receivers are different, but that doesn't matter for a conversion device. Just Form 2 the packs like Law Dawg Armory did. 

I believe both the FS2000 and the PS90 factory stocks have a selector that prevents the trigger from pulling back far enough to engage these packs into a full auto mode.

These packs are like steyrs that when in select fire mode, you pull a little and get a single round - pull further and it goes into FA.

So, you need a selector that allows FA for one.

Second, I believe, the factory non select fire stocks, apparently are designed to prevent you from installing a select fire selector into them. I have no clue what changes / modifications need to be made for that.

From Googling, I don't think there's anything to prevent installation/function of the selector switches, unless there's some newer generation of semi-auto stocks. I found no mention of that. Everything suggests they will swap easily, and allow greater rearward movement of the trigger bar.

Thanks for all of the replies.  I will let you know how it turns out once I get the parts.