Quote Originally Posted by SteyrAUG View Post
That tracks. I knew there were QC issues on the 556 where in some cases both gas settings were identical, so I understood why somebody might replace those but didn't think about somebody fine tuning a Swiss rifle.
I find the standard gas setting on my 551’s to be fine (both are 2022 made JDI imports). I do not run them suppressed though.

For the 553R I own, I’m interested in a setting with a larger hole for use with Hornady Subsonics. My 553R starts having hiccups on 1.2 and 1.3 settings. I use an OSS/HUX-WRX can though, not a baffled can. On 1.4-1.5, the 553R runs great and gives me a standard AK pattern ejection with brass and high quality steel cased (read: not Tula).

I have not shot my 550s yet. No time due to work.