I don't know effective it will be but I know it will be quieter. The theory to me is the gas will expand in the chamber of the brake then slam into the flat bottom to help reduce recoil. Really does a .223 have that much recoil that you need a brake. Beside I don't have suppressor to screw on it so I'll have to settle for a brake.
I know they work. Not as well as a regular brake but they work. Your explanation sounds good and is sort of what I was going with. As far as the guy from the video, it sounded like he was a competition shooter. Anything to speed up the shot and increase accuracy is a big deal to them.
Nice video! It’s so satisfying to build up a rifle, and develop a load that suits it. I got lucky.. my first AR build (and my ONLY AR build) turned out to be a 1 MOA shooter. I’m quitting while I’m ahead, LOL! It was fun to watch this stiff, Six!