I bought four AAC suppressors back in 2012 that used the 51T and 90T QD interface. It became apparent that there was a problem with the QD design and I set about modifying one of them to see if I could improve the situation. In 2018 I sent the M4-2000 to a machine shop along with a drawing to have the suppressor modified to work with a SilencerCo ASR or Dead Air KEY-MO adapter or any other interface based on the 1.375-24 thread pattern. I made a post about the upgrade here.
AAC QD suppressor upgrade | The High Road
It worked well but I was pleased to see that @MachIVshooter of ECCO Machine started offering a similar but more robust upgrade a while later. I sent all four AAC suppressors to him and he was able to convert three of them to the 1.375-24 pattern. At that time he wasn't set up for welding titanium, but that recently changed and I sent the Mk13-SD off to CO a few weeks ago. I picked it up yesterday and once again the work is outstanding. At my request he changed the color from FDE to OD Green. After almost 10 years of ownership I finally have all four AAC suppressors where they need to be and I'm happy about that.
The upgraded Mk13-SD is shown at bottom along with a SilencerCo Omega 300 and Harvester. The weights with AREA419 adapters are from top to bottom 15.20 oz, 12.05 oz and 15.40 oz.
AAC QD suppressor upgrade | The High Road
It worked well but I was pleased to see that @MachIVshooter of ECCO Machine started offering a similar but more robust upgrade a while later. I sent all four AAC suppressors to him and he was able to convert three of them to the 1.375-24 pattern. At that time he wasn't set up for welding titanium, but that recently changed and I sent the Mk13-SD off to CO a few weeks ago. I picked it up yesterday and once again the work is outstanding. At my request he changed the color from FDE to OD Green. After almost 10 years of ownership I finally have all four AAC suppressors where they need to be and I'm happy about that.
The upgraded Mk13-SD is shown at bottom along with a SilencerCo Omega 300 and Harvester. The weights with AREA419 adapters are from top to bottom 15.20 oz, 12.05 oz and 15.40 oz.
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