I'll sum up my take on this topic in the following way:
In July of 2009 our SWAT team (of which I am a member of) was involved in a prolonged exchange of gunfire with a barricaded suspect in Alvin, Texas. We were called in to assist our sister city because the suspect had fired upon patrol officers who were responding to the scene of a shooting where one person had been shot by a lone gunman.
As our team arrived on scene (approximately 45 minutes after the initial shooting..0100hrs), we were immediately met with gunfire from the suspects residence. We quickly set about relieving the patrol officers who had held the perimeter since inception. Approximately 40 minutes after taking a position on the rear of the home my partner and I heard a loud "Pong" sound just off to our left. The sound that we heard was later discovered to be a .45 caliber slug striking the steel overhang that we were positioned beside. Immediately following this, we observed a hand (with gun attached) protrude from the kitchen window of the residence. The "hand" aimed itself towards the react team that was stacked on the D side of the house, facing the front door. My teammate and I reacted at approximately the same time and began putting rounds on the hand. Our issued duty rifle is an 11.5" Colt Commando with an A2 FH. I was kneeling in a position directly over my teammate who was prone with my muzzle approximately 15 inches over, and in front of his head. His muzzle was below, and about 35 inches in front of me. After an exchange of approximately 15 rounds, the suspect withdrew and began screaming wildly as if he had been hit. I, and my teammate were nightblind and our hearing had suffered a substantial drop in ability as a result of the first exchange.
Over a period of 3 hours we had numerous other exchanges of gunfire with the suspect at the windows of the house. Unfortunately, his house was constructed of sand filled cinder block with concrete/fiber board exterior. None of our .223 rounds (Winchester 55 grain ballistic tip) penetrated the walls of the house and the suspect only suffered several minor glancing superficial wounds to his hands. On a positive note, the suspect did eventually stop firing and came out of the house in a "Polish Hostage" type situation where he was duly bean bagged by the react team and taken into custody.
As a result of the lessons learned from this encounter, our Department has now equipped our Colts with YHM Phantom suppressors and our duty round had been changed to 64 grain Speer gold dot (soft point). All things being equal, I think the flash was much worse than the "bang" from the encounter but both proved to be detrimental to our operational ability. I have a Sig 556 SBR (personally owned) that I run my issued Phantom suppressor on from time to time and I can't tell a difference between the commando and the 556 suppressed. I can say that flash on both is completely eliminated and sound is greatly reduced allowing verbal comms to continue while engaging. You can definately appreciate the difference when shooting indoors or on a covered range.
If you need either of those two advantages then by all means suppress away. As Ullie said, you will not achieve "Hollywood" quiet but it will make a huge difference operationally. If you want Hollywood quiet, buy a .22 rifle and Gemtech Outback II.... Shooting sub-sonics it is truly hollywood quiet and a boatload of fun 8)
FWIW
