Good to know.once the cans got under 140db they all start to sound the same, maybe due to sonic crack. So for a rifle can all I care is that the platform intend to run gets under 140db, then I begin to prioritize weight, length, mounting options, blow back. durability, etc... I actually liked the micro cans in 556 I've played with.
Also once cans that shoot primarily subsonics get intot he low 120's its hard to tell the difference between a 118db shot and a 125db shot, IMO, so it becomes more important to listen for tone. For example the leonidas metered lower than my 44spl subonics, but the tone of the 44 is lower IMO. the 38 spl lever action I have meters lower than my 44 spl, but again the 44 tone is very low and generally more impressive.