P90/PS90 Differences

[zpat]

I spent about 9 months converting my H&K USC into a UMP. I just got there with my final polymer welding done which put the folding stock "clip" onto the gun, something that only a handful of people have done. If you really go all out, the amount of differences is so minute it is crazy. From the outside, my gun is 100% identical to a UMP, with just a few small internal changes.

I want to move on and finish my PS90->P90 conversion which I started 6 months ago. My tax stamp just got back. In the H&K world, we are fortunate enough to be able to have the full auto selector switch because we can buy the UMP lowers (which is cosmetic only since you swap out your full auto internals for your USC internals unless you want to go to jail). Is there any way to get a P90 selector switch so it shows the three settings? Anyone know the exact number of differences between the PS90 and P90 or have a link to point me to? The things I know are different: trigger group, selector switch, barrel/shroud and flash hider (which are relatively easy to change out to nearly identical).

Does the P90 trigger group work in a PS90 and vice versa?


Appreciate any/all pointers.

[jhs27275]

You can get the three position "look" selector here.

F2K/FS2K & P90/P90 3 Position (look) Fire Control Switches

A lot of us know the differences between the P90/PS90. You'll have to be happy with converting your PS90 to a SBR.

Talk of converting the PS to a P will get you booted from the forum.

[zpat]

To be clear, I am talking about converting my PS90 to a P90 WITHOUT any full automatic, a totally legal version. I thought that was clear--obviously not. Why the secrecy on what the differences are? This kind of stuff is discussed all the time in the H&K world, I'm confused...

[jhs27275]

A true P90 even without the full auto is still classified as a machinegun.

And this is not the H&K world.

[gbosh]

With it SBR'd and the cosmetically altered selector mentioned, you aren't going to get much closer legally unless you are a properly licensed SOT. If you are going for external appearances, you're already there when you (legally) put the short barrel and correct flash hider on it. Hammer packs are interchangeable.

Rails and optics are varied and possible on either version.

Part of the 'rub' here is in calling it a P90 which has implications that are not palatable to the site admins and users. HTH!

[zpat]

I'm obviously not talking about a "true P90", I'm talking about converting my PS90 into as close as I can get to the P90 as legally possible. And the forum rules are pretty clear: "One of the main topics NOT allowed on FNForum.net is one of converting the PS90 or any other semi automatic firearm into a fully automatic one." Since I am not talking about converting into a fully automatic, I see no reason why this topic would not be allowed.

When you put forward the truism above, were you attempting to imply that the FN world is not as open and helpful as the H&K world? Not sure how else to read that. Regardless, it would be great if some folks would offer some helpful information since I'd imagine this is a topic that others might want to pursue.

[SgtStrykerUSMC43]

To be clear, I am talking about converting my PS90 to a P90 WITHOUT any full automatic, a totally legal version. I thought that was clear--obviously not. Why the secrecy on what the differences are? This kind of stuff is discussed all the time in the H&K world, I'm confused...

You can do a PS90 SBR and as jhs mentioned, I offer the "look" switches to complete the "look".

-SS

[jhs27275]

I'm talking about converting my PS90 into as close as I can get to the P90 as legally possible

Then SBR it and you're there.

[zpat]

What about external markings? For instance on the H&K USC, really hardcore "converters" go to the trouble of having the polymer markings removed and replaced with UMP. I did that. Are the markings on the PS90 different from the P90 in any way? The metal engraving of PS90 on the receiver would be a tough nut to change but might be possible. On my polymer stock I only have FN Belgium and the US marking. Is the P90 the same?

Thanks for the tip on the 'rub'. If the rule changes to say I can't talk about a P90, I'll drop it. Until then it is quite difficult for me to convey what I'm trying to do without saying P90. To be clear, AGAIN, I'm talking about converting my PS90 into a P90 look-a-like WITHOUT the full automatic. Something that people do all the time with AK47s, H&K UMPs, and dozens of other firearms.

[zpat]

So is that really it? As I mentioned above, the marking on the metal receiver is certainly different. Is there anything else? What I'm referring to is fine details. If people don't know the answer, that's fine. But to say just SBR it and you are done, well, that's clearly not true.