Anyone played with barrel length and suppressors?

[AR_Hunter-Reloader]

I built a 12.5” pistol setup using a BA Hanson barrel firing through a Deadair Sandman S. It’s just barely hearing safe with the Hornady 123’s. I added a Superlative Arms adjustable gas block to help vent some of the gas. Still just barely hearing safe. I’m considering building a 18” or 20” setup if I can make it quieter. I’m trying to build a rig that can be used with a hunting partner, wife, right next to me without too much noise. The can does a good job on my 16” 300 BLK.

Any advice