This is a great example of a bad "scientific" test. It only "proves" that if you hang more weight on the end of the barrel you'll get less muzzle rise. IF you want to see what the comp does, or doesn't do, try this "test" with the comp "clocked" normally, ports up, and then with the comp rotated 180 deg. Ports down. Muzzle weight will be the same so you'll see the ports' effect, or lack of effect. A comp with effective porting is also pretty amusing to actually shoot (no ransom rest for this) with the comp rotated 90 degrees so it pushes the muzzle sideways...