Let me first apologize if this was previously discussed, I searched all the ways I know how and have access to and could not find anything.

So, my PS90 reciever cracked. I found a guy selling a replacement reciever but he has it labeled as a "P90/PS90 reciever". I, admittedly, am fairly ignorant about the p90, except to know I want to avoid a owning anything that qualifies as a machine gun part, however I always kind of assumed that the parts that made the P90 full auto were in the trigger pack and/or bolt  carrier.  But, I want to be sure before I make a purchase... hence my search for knowledge.

So, here are my questions:

1. Is the reciever itself universal or interchangeable between the two?

2. If not, is the 'p90' reciever legal to own? Is it devoid of any of the full auto features that will land me in jail?

3. If not, how can I tell the difference? What should I look for on this reciever to determine which type this reciever actually is?

1.)  The receivers are not interchangeable. For ATF to approve the import or sale to us lowly tax serfs, the receiver must not be capable of accepting full auto parts     without machine work.

2.)  A P90 receiver, if it has ever been registered as a machine gun, may not be transferred to a tax serf. These are reserved for the use of the King's men only.

3.) Can't help you on the visual ID of the P90 vs. PS90 receiver. Someone more knowledgeable than I will have to answer that for you.

Simple, a P90 receiver is marked "P90"

A PS90 receiver is marked "PS90"

BATF's position is "Once a machine gun, ALWAYS a machine gun.

How in the hell did you crack a PS90 receiver as there is almost zero stress on one?

There are aftermarket billet receivers out there, not cheap but available.

This may be an aftermarket, possibly without the markings, at least not that I saw in the pictures. I'm going to look at it in person this weekend. $199 is hard to pass up for a new reciever, but I don't want to risk having an illegal part.  Either way, I'd rather not gamble jail time on the ignorance (mine or the sellers) of it possibly being mislabeled.

Do you have a pic or a link?

If you're not an ATF agent trolling, then you should listen to your gut which is telling you to run away.  There's nothing good that can come of this.  And how the hell did you damage a PS90 receiver?  If you really cracked it, why aren't you asking about sending it back to FN for replacement?  You're really coming across as a

First off, I've never heard of a PS90 receiver cracking. The stock yes, but I don't know how you could manage to break the actual receiver. The only difference between a P90 and PS90 is the barrel, stock, selector, and FCG.

Not sure how asking questions is 'being a troll', but last I checked knowledge isn't illegal, and neither is answering questions, so even if I were an ATF agent (who joined this forum 13 years ago), nothing I've asked and none of your answers, would be cause for legal action against either of us. Fortunately, I don't take offense, as I am willing to attribute most of this to a level of paranoia I'm used to seeing on this site, so no hard feelings.

That being said, and now that we are, hopefully, past the name calling, I have one final question...

If the only difference between the reciever are the markings, and there is no mechanical difference, and nothing about the p90 reciever that allows it function any differently than the ps90 reciever, why is it illegal? Or is this just one of those things I should write off as illogical  governmental beuracracy of laws written by people who know nothing about guns?

One thing would be that any receiver marked P90 was built/registered as fully automatic, and since there are no transferable P90s the law looks at it as "once a machine gun, always a machine gun"

The above comment is DEAD ON!!!

Another example...

The ONLY difference between an M-1 Carbine (semi auto) receiver and an M-2 Carbine (full auto) receiver is the markings.

I was a Class III NFA Dealer for almost two decades, BATF does state ONCE A MACHINE GUN, ALWAYS A MACHINE GUN!!!