I haven't tried the AAC, but the Gemtech M4-96 rocks -- both the thread-on and the QD model. Extremely quiet, and very durable.
FWIW, besides making first-rate cans, Gemtech has maybe the best customer service in the suppressor industry.
For example, last fall I sent a .22 1911 conversion off to them to be threaded for my Outback can. I called a couple of days later to make sure it arrived, and ended up speaking directly to Phil Dater, Gemtech's guru. Dr. Dater told me it arrived but would be a week or two since there were a couple of projects in line ahead of me, which was fine. I did mention I was kicking myself for putting off sending it to him, because there was a shoot the upcoming weekend where I could've used it.
At 8 a.m. the next morning, I received a shipping notice that the unit was en route back to me. I called Phil back and he told me he felt so bad about me missing the shoot, he went back to the shop after dinner, threaded my barrel, packaged it up and sent it out overnite delivery.
Everyone I know gets this same level of service from Gemtech. Which is why they have such loyal customers.
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