Finally got around to actually doing the barrel swap on my PS90. Got the blind pin out pretty easily, but soon found that since mine was an early one (came with green stock with white ring sight), it had a two piece barrel shroud and it was impossible to free the flash hider from the barrel. Ended having to cut the barrel with a hacksaw to get it off. Thought I might have damaged the receiver, but ran it yesterday, and it was 100% reliable with FN and Fiocchi ammo.

Ran it suppressed with a Hux Flow 556 Ti, and was completely……..unimpressed. Very little change in volume from unsuppressed. Granted, it was an indoor range and I was shooting supersonic ammo, but I felt like I got a lot less volume reduction than shooting my X95 with 55gr 5.56 and my Hux Flow 556K at the same range. Not sure what’s up with that.

This message has been edited. Last edited by: Dwill104,

Nice...

Looks great. I need to finally pick one of these up. Just swish they offered a factory SBR option.

Bummer about the lack of obvious benefit of the suppressor. I thought a low backpressure can would be best for this host, but perhaps a slightly higher backpressure can would have a greater impact.

This message has been edited. Last edited by: Vgex,

100% it’s the can. Shooting subs, mine sounds very quiet with my Griffin Explorr and hilariously quiet with my Polonium. The action noise being right up against your ear, I’d say it’s not “hearing safe” as the shooter, but mine was quieter than a lot of the 9mm suppressed PCC’s my friends brought out to a suppressed PCC day we did last summer, including some B&T integrals.

I need to get some subs. The suppressor was my first through, but for all the carping about the Hux cans sounding bad, the 556Ti did pretty good at Pew, and I’m having trouble believing that a long 1.8 inch diameter 5.56 can can’t do anything for the lower pressure 5.7 cartridge. As I said, a flow can did a better job with 5.56. Maybe it needs a certain amount of pressure to work right.

I’ve got to do some more testing and get some subs. I’ll try out the 556K and see if that makes a difference. If that doesn’t do anything, I’ll have to change the muzzle device and try some other cans. I was originally going to use a .30 cal Griffin Explorr, but I went with the Hux Flow because they are still the lowest backpressure cans, and there have been reported issues with conventional cans (stock cracking and the mag popping off) that I wanted to avoid. Also have some other low backpressure cans to try out.

Yeah, I’ve heard of that, too. It’s why I don’t do a lot of shooting with the Polonium on mine, despite how good it sounds. The Explorr lives on it, and it’s plenty quiet, cycles less violently.

My experience with flow through cans is limited, but the bit of shooting I did at an indoor range with a Hux can on an AR, it seemed loud. They’re not as quiet at the muzzle, and quieter at the ear because of the reduced backpressure. At an indoor range, all that sound is bouncing around and it sounds louder no matter what it is. I’d guess if you shot it outdoors, it would seem far quieter. The Fiocchi 62gr loads are good stuff. Grin inducing for sure.

Such a neat design. They make those magazines work using black magic.

I had forgotten that the mags were kind of a pain to load fully. The last time I shot it was years ago.

I have always wanted a SBR PS90. I hope to have one someday, but it's so-far remained unjustifiable, when compared to other purchases. And it's always been, for some reason, in direct competition with a B&T USWA1, which I would almost certainly purchase first.

quote:

Originally posted by Dwill104:
I had forgotten that the mags were kind of a pain to load fully. The last time I shot it was years ago.

I hear you. I thought about changing the rollers out on mine, to see if that helps.

Do you still have the white dot for it? How did you like it? I thought about getting one for mine. I have a rail and seems kind of high off the bore so I have to gage my view/shots.

quote:

Originally posted by flesheatingvirus:
Such a neat design. They make those magazines work using black magic.

I just bought a current PS90 and all of my mags (newer production) are easy peasy to load up to 50 rounds.

quote:

Originally posted by patw:

quote:

Originally posted by Dwill104:
I had forgotten that the mags were kind of a pain to load fully. The last time I shot it was years ago.

I hear you. I thought about changing the rollers out on mine, to see if that helps.

Do you still have the white dot for it? How did you like it? I thought about getting one for mine. I have a rail and seems kind of high off the bore so I have to gage my view/shots.

I have the Design Machine Lo Mount incoming for my MRO. It’s supposed to get the optic almost an inch lower than the stock PIC rail and provide a normal cheek weld.

I have a couple of these sitting in my project todo list. Tell me more about the two piece shroud? one of mine is very old. I searched but can't find anything. You get the pin out and then you cannot unscrew the shroud as normal?

quote:

Originally posted by patw:
Do you still have the white dot for it? How did you like it? I thought about getting one for mine. I have a rail and seems kind of high off the bore so I have to gage my view/shots.

I'd bet a plug nickel Dwill's using the HBI mount for his particular optic. Last I checked, they're cheaper than the Design Machine mounts and I believe mount even lower.


https://hbindustries.net/store...category/fn-herstal/


I have theirs for my PA Microprism. Mine came with the FN factory red dot, just a crappy Docter made for FN. This is much better.

quote:

Originally posted by patw:

quote:

Originally posted by Dwill104:
I had forgotten that the mags were kind of a pain to load fully. The last time I shot it was years ago.

I hear you. I thought about changing the rollers out on mine, to see if that helps.


Do you still have the white dot for it? How did you like it? I thought about getting one for mine. I have a rail and seems kind of high off the bore so I have to gage my view/shots.

Do you mean the original white ring sight? It’s probably around in a box somewhere, but I hated it. Very hard to see and I replaced it with the black ring sight (aka the USSS sight) soon afterwards, which was a little better, but not as good as a RDS IMHO. Later on, I got a pic rail to mount a RDS, and my current setup is the HBI optic rail with a Holosun 503 green recticle, which I’m happy with. The factory pic rail is pretty high, but there are aftermarket ones that are a little lower. The HBI rails are direct mount made for specific optic footprints.

quote:

Originally posted by P220 Smudge:

quote:

Originally posted by patw:
Do you still have the white dot for it? How did you like it? I thought about getting one for mine. I have a rail and seems kind of high off the bore so I have to gage my view/shots.

I'd bet a plug nickel Dwill's using the HBI mount for his particular optic. Last I checked, they're cheaper than the Design Machine mounts and I believe mount even lower.


https://hbindustries.net/store...category/fn-herstal/


I have theirs for my PA Microprism. Mine came with the FN factory red dot, just a crappy Docter made for FN. This is much better.

You are correct, Sir!

quote:

Originally posted by hrcjon:
I have a couple of these sitting in my project todo list. Tell me more about the two piece shroud? one of mine is very old. I searched but can't find anything. You get the pin out and then you cannot unscrew the shroud as normal?

There is a thin seam visible where the shroud starts increasing in diameter for the flash hider. The seam is forward of the blind pin, so the pin only attaches the main part of the shroud to the barrel threads. The FH part is separately attached to the barrel threads somehow. There is some discussion in this thread.

https://www.reddit.com/r/ps90/..._this_barrel_design/

That Reddit thread is wild.

From everything I've seen, conversions tend to fall into one of a few different experiences:

• The blind pin weld drills easy, and drifting it out is a piece of cake.
  
  
• The blind pin weld requires lots of drilling, and doesn't drive out easy at all.
  
  
• All known methods fail and you end up having to cut the thing apart with a saw and the original barrel is a complete loss.
  

I was in the second category. I went back and forth with the drill and the punch over and over and finally got the pin to start drifting only to eventually snap the punch off in the hole. Thankfully, that came out without much drama. Getting the barrel to unthread was easy enough. Supposedly, the original barrel isn't worth keeping once you take it apart, but I went ahead and saved mine anyway. If desired, I can dig it and the shroud out to take pics. FN definitely didn't make it easy with these, that's for sure.

Scrolling back and forth, I see some rather significant differences in the castings of our uppers. What serial range is yours? Mine is 120XXX, purchased in 2018.

I have a mill so the one I already did I just milled into the area above the pin to get access and it drove right out. I'm using the FN factory flashhider and a B&T 5.7 can FWIW.
I just didn't know that two piece ones even existed so I have to look into that before I do the next one. I also use the HBI mount and have been happy with it.

once upon a time (back when I was a 5.7 addict) TROSUSA offered to cut the factory barrels I don't know if they still do it.