I recently received my Surefire SOCOM II 7.62 RC2 can. I haven't spent much time w/ it so I'll do the best I can for you. As a disclaimer, I'm also no suppressor expert either.
I realized in my research for a suitable suppressor that no can does everything the "best." I realize it's not as light or as quiet as a TBAC Ultra model, but those weren't the only factors I was looking to cover. So, I decided what was most important to me, for my personal requirements. I'll start w/ the reasons I chose this model:
I made a pro / con list & this can best met my personal requirements
1) Will be used on multiple weapons ranging from 5.56 to .300WM
2) Bombproof (suppressor can literally be shot off the barrel if stuck)
3) Reputable company that will be around forever
4) QD attachment (mount is rock solid)
5) lack of first round pop & flash
6) Suppressor can be run wet w/ little water to mitigate flash
7) SFMB works well on its own
I realize that other muzzle brakes like the Area 419, APA, etc work better as a stand alone brake but I'd already planned to go w/ the Surefire can for the reasons stated above.
Shooting the 308, the can was noticeably quieter than the 5.56. One of my buddy's was inside the range building & he said he could tell a huge difference between the 308 & the 5.56. I really didn't shoot the 308 much as I need to adjust the eye relief on the optic so I didn't shoot but a few rounds. My son shot the 308 much more & in my opinion the gun was quite a bit quieter. From looking at the target & my 13 YO shooting I have no reason to believe that the gun won't shoot at least as well w/ the can as w/ out. This gun was built at Accuracy Unlimited & shoots very well.
As for the 5.56 gun, its a DDM4V1. It has a 16" barrel w/ a stock trigger at the time, but I've just installed a Geissele SD-3G trigger. It shot well enough at to confirm my new zero at 50M. I only added .5 MOA & everything is zeroed well enough for my purposes. This certainly isn't my finest work, but this is not shot from a bench either. This is prone un-supported w/ no sling or bipod & I did call the two I shanked. Forp optics, I’m using an AimPoint T1 w/ 2 MOA dot, which pretty much covers the whole circle at 50M. The 5.56 is a tough round to suppress. This is still louder than a .22LR, but the can does do a very good job of mitigating the rifle's report.
***No instruments to measure decibels, etc so no data there.
Any questions send me a pmail.