I have a 7" can I've shot on my 204 Ruger and .223. The 204 has a 24" barrel and its really quiet even on an AR platform. I don't have a sound meter but its quite enough to shoot without hearing protection for extend periods of time without discomfort. The .223 is a 14.5" barrel and I prefer to wear ear protection when shooting it with the suppressor. It's moderately quiet with that short barrel but I still prefer to wear hearing protection. I have a YHM Turbo sitting on the shelf that states some very impressive numbers for being short and cost effective. Haven't shot it yet. The folks at Capital City Armory told me length is more valuable than diameter for reducing sound. I don't care to use suppressors longer than 7" for hunting and I also prefer lighter weight ones. On my magnums and 338 NM, I still wear hearing protection when using a suppressor. 140 db is pretty loud.