[Theohazard]

Originally Posted by Drm50

Are you allowed to build your own silencer from scratch with the permit?

Yes, but it’s not a permit. It’s a one-time tax payment of $200 and the silencer is registered to you.

Originally Posted by Drm50

And does it need
a serial number like when you build a gun from scratch?

Yes, it also needs to be marked with the caliber and with your name and location (city, state).

Originally Posted by Drm50

The only experience I had with a
silencer was a GI model for m16. Where it came from I don't know but it had gone through
several hands before I got it. The guys that had it prior to me were to dumb to know it needed subsonic ammo to work.

Almost nobody who wants an effective firearm uses subsonic ammo with .223/5.56. Subsonic 5.56 is barely better than a .22 LR and it won’t cycle the action without modifying the firearm. It’s really not a thing beyond range shooters who want the novelty of a super-quiet, single-shot rifle. I’ve worked at three gun shops over the last 7 years and I’ve only been asked for subsonic 5.56 ammo by people who had no idea of its terrible ballistics and the fact that it would turn their rifle into a single-shot. And once I told them they had no interest (we didn’t carry it anyway).

So when the military (and almost everyone else) suppresses their 5.56 rifles, they’re using supersonic ammo. You still get the supersonic crack, but the overall sound is much quieter.

Originally Posted by Drm50

After a few guys used standard ammo and full auto to boot
it was burnt out before I got it.

Even the very first centerfire rifle silencers designed by Maxim were intended for use with supersonic ammo. If that silencer you’re talking about was shot out it was either because they shot too many rounds through it too quickly, or because the silencer simply had reached the end of its service life: Every shot from a centerfire rifle erodes a silencer’s internals a little bit and eventually the performance is degraded. This usually takes many thousands of rounds, though.