Title says it all. Looking for suggestions from folks. What do you use?

Thanks!

I haven't tried it out yet, but Federal has recently released some .308 subsonic.

I don't think you'll find any 5.56 subsonic, but I could be wrong.

I use the Lapua .308 subsonic.
I have never used any 5.56 sub.

There are plenty of choices.
TrueShot ammo
Some goodies here, S&B has their 200gr offering, which is a good one.

Federal 205gr is my FAVE but I can’t remember where I picked up up at. It proved to be *very* accurate.
The HSM 175gr is okay but inconsistent out of my rifle.

This was a search for 5.56 Subsonic
Many are spotty on inventory…bring your wallet!
I haven’t personally tried any of these offerings. So far I’ve been content just taking a bit of the blast out of supersonic ammo.
Same with Beck ammo, haven’t tried it.

Atomic Ammo has some 5.56 subs but they are geared towards bolt/lever guns, not semiautomatics. They don’t create enough pressure to cycle semis.
I’ve only tried shooting 77gr SuperSonics with my new can. Quieter but still need ears on for those.

I found a subsonic 556 years ago from a vendor I do not believe exists anymore. If I come across the box I'll post back. Its out there but niche may not describe how minuscule that market it.