^^^^ Herd that too... at 8.3" bbl not easy to run well... just hope someone has success at a workaround etc.
A lot of people use muzzle brakes as sacrificial blast baffles to help protect the actual blast baffle of the suppressor. Since the muzzle brake isn’t a registered part (nor welded into the silencer), you can replace it easily as it nears failure.
I’ve never suppressed a HK53, but a Huxwrx Flow 556k might be worth looking into for several reasons:
1) no barrel length restrictions;
2) extremely low back pressure;
3) has features to make it self-tighten during use which might be helpful for full auto strings;
4) it has been tested to pass 6 cycles of “SOCOM Reliability Stress Test,” which seemingly refers to the SURG testing protocol; and
5) it uses a folded-path design without typical baffles that purportedly makes it more resistant to wear.
However, it is not the quietest suppressor out there, though I suspect nothing will be that quiet on an 8.3” 5.56. Nonetheless, I like mine a lot since the AR I have it on still acts more or less the same without requiring a lot of tuning. No harsh cycling or gas to the face. I haven’t gotten around to trying it in full auto yet.