MrTea

@Rogerborgalready have done, been on the receiving end in a very small room (like downstairs toilet size) with no ear pro. They produced a more (Airsoft) thermobaric boom than the crack of a mk5. They aren't readily available anymore as the person who was making them stopped. 

Tag inn frags, f**k them though. 

This is why I've started wearing hearing protection, even in woodland games. I blame the Youtuber "Destroying" opponents mentality.

Hi again all. Apologies for not checking back sooner. I wrote my question before I rushed off to work so i'll add some additional context below;

So i've ordered an Ohshiboom for indoor site use (cannot be bothered losing expensive BFG at an outdoors site and the BFG is more cost effective). I was informed that BFGs can use different calibre of blank/primer which have produce a different sound pitch and Db level with .209 primer being quietest or on a similar noise level to regular pyro with 12 gauge being on the opposite end. I was told it's "slightly" louder than regular pyro but produces more of a low pitched "boom" rather than a higher pitched "crack" of the other blanks/primers.

Clearly, this person was underselling how loud 12g is, especially when the noise if amplified by being in rooms/enclosed spaces. Looks like i'll be sticking with the .209 primer base it comes standard with.

Thanks for the info all and forgive my ignorance.