Do you want it to be quieter or louder?
Do you want a slightly higher velocity from your rifle.
The answer is RC2 no matter what barrel length you choose. Only use a surefire muzzle device with labyrinth seals. Like the 3 prong. The warcomp sucks and the mount will leak.
Are you proposing to do an in-depth study on the above items and provide all pertinent test results here? If so, yes, you have our approval to start the project.