Do compensators and/or muzzle brakes make a difference on a 9mm blowback type PCC? I just got a Palmetto AKV which I'm having fun with, but the "tanker muzzle brake" seems to do nothing. It has huge side ports and a couple of small vertical ports. When compared to a higher powered rifle round, or shorter pistol barrel compensator the brake on this PCC seems useless. This thing has a little smoke come out the holes, but compared to visible gas jets out the AR or pistols comps/brakes, it seems like nothing of consequence comes out the holes in this brake, and definitely doesn't feel any different with the brake on or off(at least to me).

So the question comes to is there even enough gas pressure from a 9mm after 10+ inches of barrel length to make a comp or brake actually worth it, especially on a weapon 3-6 times heavier than a pistol normally used to shoot 9mm?

And that being said, even if there is enough gas pressure left to make a comp or brake work effectively, it would seem that most of the recoil of a "blowback" bolt PCC is caused by the heavy bolt movement/stoppage, which occurs "after" the bullet and gas pressure has already left the barrel. So in my brain, blowback PCC's make the comp/brake even more useless.

I don't know about locked breech PCC's being more effective with comps/brakes. Just seems blowbacks wouldn't really benefit. I personally am going to remove the "tanker" muzzle brake off this AKV and just put on a thread protector, because I can't feel the difference, and I would rather have the overall length of the gun an inch shorter than keep on a brake I can't seem to notice a difference with.. Unless of course I'm wrong about it and/or there is a comp/brake that actually works and doesn't cost an arm and leg.

I never noticed any difference on my Scorpion when I changed the flash hider to a 3 lug adapter without any vents/cuts/holes. The 9mm is pretty mild to begin with and unless you have a full auto, I can't imagine any real difference.

Comps and brakes reduce recoil on 9mm PCCs, but their effects vary. I can't speak to your muzzle device.

I have a 9mm blowback PCC with an 8" barrel, which I shoot with a SilencerCo Omega 9k can. The Omega 9K is not the quietest can, yet it noticeably reduces recoil. Recoil reduction seems similar with the supersonic 115/124 loads and the subsonic 147 grain loads.

In general, suppressors reduce recoil less than well-designed brakes.