DL. wrote:I picked a nice if not slightly hot day for this. 26 - 27 degrees. No real breeze noticeable.
The rifle today was my sako finnfire.
I fired RWS and CCI subsonics through a mae rimfire sound moderator. I know from experimenting with the chronograph that the RWS are approaching 100 fps slower than the CCI and as a result to my ears are noticeably quieter.
I also fired some remington high velocity ammunition through the sound mod, without a mod and with a muzzle brake.
The results - most of the readings for all the ammunitions types and rifle configurations were 85 decibels.
I think this rings true of some of the comments above that a cheap sound meter can't catch a gunshot, as the difference in noise levels was pretty apparent.
I looked into this a while ago whilst running different moderators and trying to test the sound moderation.
The impulse gunshot happens at it's peak much quicker than a lot of sound meters can sample audio, since they sample at a certain frequency, the gunshot can easily pass between samples, or certainly the peak of it can.
The MOD put together a document for their authorised method of testing moderators which requires a specific sound level meter. I looked into hiring one, as they come in at around £2k+, but for a hobby it wasn't worth the expendature.
I wish I could remember the details, but it was a few years ago now :(