So 7 months later..... I have tried the Raptor SD, the new gen BCM and the G$ SD. Raptor was at the bottom of the list. I think the BCM and G$ are tied for whatever mitigation they bring to the table. I ended up liking the G$ the most not for its gas mitigation but for it's ergonomics. I'll eventually sell by two BCMs and replace them with G$ CHs. I ran these all on various length rifles (5.56 - 14.5, 11.5 and 10.3 7.62 x 39 - 11.5 and 16) using a Rugged 7.62, Polo 30, Polo, Polo K and YHM Fat Cat. (I did play with a buddy's Ventum 7.62 and thought it was noticeably louder than the Polo on a 5.56 gun. But was also shooting indoors so that may have played into it.)

When shooting outdoors, especially when running and gunning like in a CQB set up, I don't think it really matters all that much. Assuming the rifle is well set up. If you are stationary (shooting strings from supported or a barricade rest) it starts to get a little more noticeable depending on which way the wind is blowing. Shooting indoors in a booth when your ejection port is facing the wall? Absolutely. And I think this is where some folks (myself included during the conjugal visit period of my can ownership) make the mistake of labeling a can as being "too gassy." The can may very well have high back pressure, but directing the gas to a wall that your face is 2 feet away from is only going to amplify the effect.

Ultimately the conclusion I came to was that a CH can make an impact, but not as great of a one as their manufacturers would lead you to believe. It's part of the overall set up, but not THE part that is going to solve all your gas issues. So buy whichever one works the best for you as a CH first and foremost.

Next up, I ordered a BRT tube for my Colt barreled 10.3 to try out. But gas has to go someplace, right? And now that the Ventum 5.56 is out....... Kid will just have to go to a state school.