I am a bit surprised by so many suggestions to use sound supressors. If I have to enter the snake's nest, I want to create as much noise, light, commotion, and distraction as I possibly can. I want the opponent to be overwhelmed and freaked out when I open fire. If I could I would probably have a few flash grenades thrown in first, and then have a barrage of noise from all directions. Then I would throw in some noise-making, deafening whatchamathingies. If I could, I would also want to have the noisiest weapon on the face of the earth. I would want it to make hellish screams as I fire it. Maybe there is some kind of an SMG round that accomplishes that, I don't know (kind of like a tracer, except producing satanic noises) that could be inserted every 5 normal rounds. Or maybe there is something that kind of looks like a supressor, but is in reality an exhaust-gas-operated noise contraption. I would want the level of noise to physically hurt and disorient.
In short, I do not want them calm and composed, I want them hysterical.