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I’ve been fascinated by the P90 platform ever since I had a chance to shoot a manufacturer rep’s at a range day decades ago. I know the 5.7 has severe limitations, but at least it’s more available these days - back in the 90s it was unobtainium.
But…
What’s involved in physically converting a 16” PS90 to a SBR? Is it just a barrel swap?
I've thought about doing the same just because it's a really neat gun.
I believe CMMG used to make a 10" barrel for it, not sure if they still do. Most people use a gunsmith to install it.
Or, you could just have a gunsmith cut down the 16" barrel. I'm sure ADCO could take care of it, if you don't have someone local and need to send it out.
So note that unlike the AR-15, the upper is the firearm. So it'll need to be shipped as such.
I was just searching for info after posting that, and it looks like CMMG is still doing a replacement barrel.
A PS90 SBR would be a true luxury toy, but I still have the wants. Toys have a place, especially now that you can actually afford to feed them.
Medical limitations that developed the last couple of years have put major caliber rifles and shotguns out of my path for good. I have to limit long guns to things like .22LR, .22WMR and the 5.7 so I dove into the PS90 a while back just to have some long gun with at least pistol caliber terminal ballistics. I have not done the SBR but it is not as simple as rebarreling an AR, certainly people have done it on their own. CMMG is the barrel source.
It is just a barrel swap to get to SBR and I think the flush fit CMMG's take you from 16 down to 10.5 when installed. With the 16" in place it is barely a snitch over the 26" limit.
With the advent of Palmetto's AAC line the ammo has become much more affordable than even pre-pandemic times. Fiocchi who was loading for FN has established their own branded line. The American Eagle FMJ that Fiocchi is loading for Federal in their MO plant is crap for the PS90, I have had many instances of serious bullet setback, it was probably intended for pistols with a straight feed only. PSA's ammo is very accurate and about 50-100 fps hotter than the equivalent Vmax bullets loaded for the FN or Fiocchi branded ammo. It is possible to reload the cases once or twice, but I am not up for that just yet. There is a coating on the cases that will wear off quickly and then you get stuck cases or balky extraction when it is gone. This is a straight blowback action.
There are some ergo challenges for me with the PS90, but with some aftermarket parts they have all been solved. Getting one of the aftermarket low mount bases is mandatory unless you want to deal with a horrible level of offset and holdovers. There is a fix for the trigger that helps but it is still a bullpup, you are not going to get to match level triggers in these.
Other than the problems with American Eagle ammo, mine has been perfectly reliable, and with good ammo it is a 1.5 moa rifle out to 100 yards or so. Lots of fun and everybody at the range wants to give it a try. Recoil is .22WMR level.
If mine were a pure range toy I would SBR it, but I figure that this weak cartridge needs all the barrel it can get for my purposes. I am getting 2450-2500 fps with the SS198LF ammo out of the thing. I think the local coyotes should still consider me a threat.
Attachment 105157
This isn’t helping one bit. Depending how my neck fusion goes, I may need that upright mount base.Quote:
Originally Posted by fatdog
Nice adaptation to deal with a significant medical issue.
@fatdog, how's the muzzle blast compared to a 9mm carbine? I'm finding it difficult to find a house carbine my non-shooting wife is comfortable with. Unfortunately a PS90 is out of the question but I might check into the Ruger LC as long as the 5.7 doesn't have 5.56 blast. It's been 15 years since I fired any 5.7 and I flat don't remember.
I would say similar, a similar volume of gas. Of course the bullet is traveling twice as fast or more. But I ditched my PCC carbine because the recoil is significantly more than the 5.7.Quote:
Originally Posted by awp_101
Ruger 57 is a nice gun, I have it on my list and have put in some trigger time with one that belongs to a close friend. They really did a nice job for what that thing is.
No experience with 5.7 in a carbine (wife, who is VERY recoil sensitive, loved her FN Five Seven pistol though, till she didn't) but if semi-auto isn't a requirement a .357 Magnum lever action carbine has ridiculously light blast and recoil if a 5.7 carbine doesn't pan out. I intermittently look at the Ruger .357 Magnum bolt actions but can't get past the current going price...Quote:
Originally Posted by awp_101
Yes, I was in CAS for many years and kept one of those. With .38 Special 158gr +P LSWCHP it is manageable in terms of the recoil. The ergos are a little tougher for me, nothing can come in contact with my jaw, I still have to shoot these long guns in an exaggerated outboard position and the Winchester 1892 is not as comfortable.Quote:
Originally Posted by Half Moon
My cheek weld was replaced with what you can probably say is an eye socket weld. What Haga Defense did for the PS90 with his cheek riser plus a little bit of enclosed foam rubber padding turns out to work very well for me. Some day I am going to experiment with a riser on the '92 stock and I think I can make that work.