Every wonder why ever gun shop that sells suppressors typically have AAC products - I do and drank the cool-aide the first time around with a suppressor - AAC M4/2000 and the 51T (bastard). I have probably 4 of those mounts and everyone is different as far as getting the suppressor to mount on it without wiggling. I also called AAC and was told basically that a little wiggle is not an issue unless it works its way totally off...well duh, but what I can say is I have had issues with wandering rounds while shooting as it wiggles its way off the mount - AKA, accuracy sucks!
I told all my friends and anyone that would listen - AAC is now the Walmart of suppressors - they are everywhere and sold by everyone so they saturate the market and sale quantity but quality - very debatable. And, then I tell them, the majority of good suppressors come from manufacturers you have never heard of.
When you buy a suppressor you are married to it until death do you part. Do your due diligence in research before buying a suppressor and if you know people that have some ask them and try them out. I can tell you that I have since purchased Thunderbeasts and can't be happier.