Apparently there was a gas operated roller delayed 9mm PCC that uses very short gas tube that pushes on gas key that unlocks a set of rollers. Does anyone know what the name of this PCC is or any shot show coverage of it?

Rock River has a .17 HMR that is similar to what you are saying... they will be doing a .22 Magnum, too.

I haven't seen one in 9mm.

It's not gas operated, just blowback, but the JP-5 is a roller delayed 9mm.

Uses many of the same parts as the MP-5 and Glock magazines.  You can even change the geometry of the roller to adjust the amount of force required unlock the bolt to tune it to your ammo.

Pistol-Caliber Carbine Perfection: JP Enterprises JP-5 9 mm

Be prepared for sticker shock, though.  It's intended for serious competition not mass market sales.

A "gas operated" and "roller delayed" are contradictory terms. It's an absurd description that cannot be meaningful. If it were roller-locked, like MG42, then sure. It would be senseless, but it would be possible.

I didn't jump into this right away because companies sometimes blatantly lie about their own products. For example, LWRC described SMG-45 as "recoil operated delayed blowback", which is equally absurd. In their case, a big government customer didn't like UMP, so they wanted basically a big .45 caliber MP5. So they included "delayed blowback" into description in order to exclude straight blowback guns like UMP or B&T. The LWRC gun is not a delayed blowback it all, it works like an SMG sized Beretta 92. But they called it "recoil operated delayed blowback" as a harmless marketing fraud. It certainly is lighter than UMP and the recoil is not as harsh, so it's a victimless crime.

Perhaps someone tried to float at "gas operated roller delayed" PCC for a funny reason too.

A number of promising delayed blowback uppers exist. The newest one is MEAN's BDB, which uses little balls instead of rollers. Angstadt and JPE offer classic roller uppers in MDP-9 and JP-5. New ones are coming, like Zenith ZF-56. But none of these gunmakers say anything about a gas operation.

A gas AND roller delayed blowback action would be entertaining.  

You could have a gas accelerated roller delayed blowback action, but pretty much mostly pointless.  No?

The Rock River Arms clearly uses gas to unlock rollers. I think the description for there system is accurate.

Do you have a link?  I'm not finding any gas operated 9mm on their website.

https://youtu.be/6dF1btM2RMw?si=e2HU0wXNfYDtj38N

No wonder I couldn't find it - it's a .17 HMR, not a 9x19mm.



ETA:  Yeah, not blowback at all.  It's a gas operated roller lock.

https://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_ID=2349



You can just see the front of the gas block peeking out of the very rear of the rail.

Fix your title, OP, it's not delayed, despite Rock River not knowing how guns work, and it's not 9mm.

Open mouth, insert...  

Indeed their system defies the taxonomy somewhat. The .17 HMR up-ends all I know about the proper design of rifle actions. For example the Savage A17 has a one-and-a-half-stage delayed blowback. It's a bit similar to Stribog A3 in that the delayed mass is minuscule. General Thompson was so close to this with the AutoRifle, but no cigar.

I think the rollers lock the bolt in place in the RR.  No gas, it's a manual straight-pull bolt action.  I don't think it's a blowback - the gas pushes the gas key rearward, unlocking the bolt, then gas continues to push the gas key to the rear, pushing the bolt to the rear.

The Savage A17 & A22 are lever-delayed blowbacks, like the FAMAS.

Maybe.

Or the gas pushes on the gas key unlocking the rollers allowing the bolt to move from the pressure of the cartridge.

The 5.56x45 cartridge base contributes to pushing the bolt to the rear as well.  We don't call an AR a gas operated delayed blowback, b/c it's locked at the moment of firing.

The Rock River is locked at the moment of firing, and if you remove the gas tube, the gun will only operate manually b/c the ball bearings lock the bolt in place.  That's a roller locked breech like the MG 42.

Gas operated roller locked vs. roller delayed:

It looks that way, but we don't know how long it takes for the movable gas key to reach the unlocked position. If the bullet is still in the barrel, it turns the whole system into a delayed blowback of sorts, but not. In a normal delayed blowback, the case head has to move in order to act upon the disadvantage (such as rollers). It moves extremely slightly - in many cases within the stretch limits of the brass. But in A17 the bolt is fully locked at first.

The designers at Savage seem to be sure that the extraction happens under the power of residual pressure on the case. It's possible that they are clueless about what happens in reality. General Thomson thought that Blish principle delayed his .45 gun. But I would not assume Savage people don't know. They could have taken a high speed footage and literally see if bolt starts to move before bullet is out of the barrel or not. You know that even Mark Serbu takes those videos. And Savage is a much bigger company than Serbu.

The main reason why 17 HMR is not suitable for straight blowback is the case shoulder. Gas pushes it against the chamber. As the bolt moves, the pressure stretches the case like a party balloon. Ultimately it can tear it.

The same situation occurs in PPSh-41 when it fires 7.62 Tokarev. But the shoulder is very small and the material is soft, so the case flows in the chamber like play-doh. Apparently .17 HMR is too thin for that.